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9 daysipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr()Will Rosenberg1-1/+2
[ Upstream commit 58fc7342b529803d3c221101102fe913df7adb83 ] There exists a kernel oops caused by a BUG_ON(nhead < 0) at net/core/skbuff.c:2232 in pskb_expand_head(). This bug is triggered as part of the calipso_skbuff_setattr() routine when skb_cow() is passed headroom > INT_MAX (i.e. (int)(skb_headroom(skb) + len_delta) < 0). The root cause of the bug is due to an implicit integer cast in __skb_cow(). The check (headroom > skb_headroom(skb)) is meant to ensure that delta = headroom - skb_headroom(skb) is never negative, otherwise we will trigger a BUG_ON in pskb_expand_head(). However, if headroom > INT_MAX and delta <= -NET_SKB_PAD, the check passes, delta becomes negative, and pskb_expand_head() is passed a negative value for nhead. Fix the trigger condition in calipso_skbuff_setattr(). Avoid passing "negative" headroom sizes to skb_cow() within calipso_skbuff_setattr() by only using skb_cow() to grow headroom. PoC: Using `netlabelctl` tool: netlabelctl map del default netlabelctl calipso add pass doi:7 netlabelctl map add default address:0::1/128 protocol:calipso,7 Then run the following PoC: int fd = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); // setup msghdr int cmsg_size = 2; int cmsg_len = 0x60; struct msghdr msg; struct sockaddr_in6 dest_addr; struct cmsghdr * cmsg = (struct cmsghdr *) calloc(1, sizeof(struct cmsghdr) + cmsg_len); msg.msg_name = &dest_addr; msg.msg_namelen = sizeof(dest_addr); msg.msg_iov = NULL; msg.msg_iovlen = 0; msg.msg_control = cmsg; msg.msg_controllen = cmsg_len; msg.msg_flags = 0; // setup sockaddr dest_addr.sin6_family = AF_INET6; dest_addr.sin6_port = htons(31337); dest_addr.sin6_flowinfo = htonl(31337); dest_addr.sin6_addr = in6addr_loopback; dest_addr.sin6_scope_id = 31337; // setup cmsghdr cmsg->cmsg_len = cmsg_len; cmsg->cmsg_level = IPPROTO_IPV6; cmsg->cmsg_type = IPV6_HOPOPTS; char * hop_hdr = (char *)cmsg + sizeof(struct cmsghdr); hop_hdr[1] = 0x9; //set hop size - (0x9 + 1) * 8 = 80 sendmsg(fd, &msg, 0); Fixes: 2917f57b6bc1 ("calipso: Allow the lsm to label the skbuff directly.") Suggested-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Will Rosenberg <whrosenb@asu.edu> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://patch.msgid.link/20251219173637.797418-1-whrosenb@asu.edu Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysip6_gre: make ip6gre_header() robustEric Dumazet1-1/+8
[ Upstream commit db5b4e39c4e63700c68a7e65fc4e1f1375273476 ] Over the years, syzbot found many ways to crash the kernel in ip6gre_header() [1]. This involves team or bonding drivers ability to dynamically change their dev->needed_headroom and/or dev->hard_header_len In this particular crash mld_newpack() allocated an skb with a too small reserve/headroom, and by the time mld_sendpack() was called, syzbot managed to attach an ip6gre device. [1] skbuff: skb_under_panic: text:ffffffff8a1d69a8 len:136 put:40 head:ffff888059bc7000 data:ffff888059bc6fe8 tail:0x70 end:0x6c0 dev:team0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:213 ! <TASK> skb_under_panic net/core/skbuff.c:223 [inline] skb_push+0xc3/0xe0 net/core/skbuff.c:2641 ip6gre_header+0xc8/0x790 net/ipv6/ip6_gre.c:1371 dev_hard_header include/linux/netdevice.h:3436 [inline] neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618 neigh_output include/net/neighbour.h:556 [inline] ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:220 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318 mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855 mld_send_cr net/ipv6/mcast.c:2154 [inline] mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693 Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Reported-by: syzbot+43a2ebcf2a64b1102d64@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/693b002c.a70a0220.33cd7b.0033.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251211173550.2032674-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysnetfilter: nf_tables: pass context structure to nft_parse_register_loadFlorian Westphal1-2/+2
[ Upstream commit 7ea0522ef81a335c2d3a0ab1c8a4fab9a23c4a03 ] Mechanical transformation, no logical changes intended. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Stable-dep-of: a67fd55f6a09 ("netfilter: nf_tables: remove redundant chain validation on register store") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysipv6: add exception routes to GC list in rt6_insert_exceptionXin Long1-0/+1
commit cfe82469a00f0c0983bf4652de3a2972637dfc56 upstream. Commit 5eb902b8e719 ("net/ipv6: Remove expired routes with a separated list of routes.") introduced a separated list for managing route expiration via the GC timer. However, it missed adding exception routes (created by ip6_rt_update_pmtu() and rt6_do_redirect()) to this GC list. As a result, these exceptions were never considered for expiration and removal, leading to stale entries persisting in the routing table. This patch fixes the issue by calling fib6_add_gc_list() in rt6_insert_exception(), ensuring that exception routes are properly tracked and garbage collected when expired. Fixes: 5eb902b8e719 ("net/ipv6: Remove expired routes with a separated list of routes.") Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/837e7506ffb63f47faa2b05d9b85481aad28e1a4.1744134377.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 daysipv6: avoid possible NULL deref in modify_prefix_route()Eric Dumazet1-6/+7
commit a747e02430dfb3657141f99aa6b09331283fa493 upstream. syzbot found a NULL deref [1] in modify_prefix_route(), caused by one fib6_info without a fib6_table pointer set. This can happen for net->ipv6.fib6_null_entry [1] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 1 UID: 0 PID: 5837 Comm: syz-executor888 Not tainted 6.12.0-syzkaller-09567-g7eef7e306d3c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__lock_acquire+0xe4/0x3c40 kernel/locking/lockdep.c:5089 Code: 08 84 d2 0f 85 15 14 00 00 44 8b 0d ca 98 f5 0e 45 85 c9 0f 84 b4 0e 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 96 2c 00 00 49 8b 04 24 48 3d a0 07 7f 93 0f 84 RSP: 0018:ffffc900035d7268 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000006 RSI: 1ffff920006bae5f RDI: 0000000000000030 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90608e17 R11: 0000000000000001 R12: 0000000000000030 R13: ffff888036334880 R14: 0000000000000000 R15: 0000000000000000 FS: 0000555579e90380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc59cc4278 CR3: 0000000072b54000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] modify_prefix_route+0x30b/0x8b0 net/ipv6/addrconf.c:4831 inet6_addr_modify net/ipv6/addrconf.c:4923 [inline] inet6_rtm_newaddr+0x12c7/0x1ab0 net/ipv6/addrconf.c:5055 rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6920 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2541 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg net/socket.c:726 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2583 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2637 __sys_sendmsg+0x16e/0x220 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd1dcef8b79 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc59cc4378 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd1dcef8b79 RDX: 0000000000040040 RSI: 0000000020000140 RDI: 0000000000000004 RBP: 00000000000113fd R08: 0000000000000006 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 00007ffc59cc438c R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001 </TASK> Fixes: 5eb902b8e719 ("net/ipv6: Remove expired routes with a separated list of routes.") Reported-by: syzbot+1de74b0794c40c8eb300@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/67461f7f.050a0220.1286eb.0021.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> CC: Kui-Feng Lee <thinker.li@gmail.com> Cc: David Ahern <dsahern@kernel.org> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
9 daysipv6: clear RA flags when adding a static routeFernando Fernandez Mancera1-0/+4
[ Upstream commit f72514b3c5698e4b900b25345e09f9ed33123de6 ] When an IPv6 Router Advertisement (RA) is received for a prefix, the kernel creates the corresponding on-link route with flags RTF_ADDRCONF and RTF_PREFIX_RT configured and RTF_EXPIRES if lifetime is set. If later a user configures a static IPv6 address on the same prefix the kernel clears the RTF_EXPIRES flag but it doesn't clear the RTF_ADDRCONF and RTF_PREFIX_RT. When the next RA for that prefix is received, the kernel sees the route as RA-learned and wrongly configures back the lifetime. This is problematic because if the route expires, the static address won't have the corresponding on-link route. This fix clears the RTF_ADDRCONF and RTF_PREFIX_RT flags preventing that the lifetime is configured when the next RA arrives. If the static address is deleted, the route becomes RA-learned again. Fixes: 14ef37b6d00e ("ipv6: fix route lookup in addrconf_prefix_rcv()") Reported-by: Garri Djavadyan <g.djavadyan@gmail.com> Closes: https://lore.kernel.org/netdev/ba807d39aca5b4dcf395cc11dca61a130a52cfd3.camel@gmail.com/ Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20251115095939.6967-1-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysnet/ipv6: Remove expired routes with a separated list of routes.Kui-Feng Lee4-15/+109
[ Upstream commit 5eb902b8e7193cdcb33242af0a56502e6b5206e9 ] FIB6 GC walks trees of fib6_tables to remove expired routes. Walking a tree can be expensive if the number of routes in a table is big, even if most of them are permanent. Checking routes in a separated list of routes having expiration will avoid this potential issue. Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: f72514b3c569 ("ipv6: clear RA flags when adding a static route") Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysxfrm: flush all states in xfrm_state_finiSabrina Dubroca1-1/+1
[ Upstream commit 42e42562c9cfcdacf000f1b42284a4fad24f8546 ] While reverting commit f75a2804da39 ("xfrm: destroy xfrm_state synchronously on net exit path"), I incorrectly changed xfrm_state_flush's "proto" argument back to IPSEC_PROTO_ANY. This reverts some of the changes in commit dbb2483b2a46 ("xfrm: clean up xfrm protocol checks"), and leads to some states not being removed when we exit the netns. Pass 0 instead of IPSEC_PROTO_ANY from both xfrm_state_fini xfrm6_tunnel_net_exit, so that xfrm_state_flush deletes all states. Fixes: 2a198bbec691 ("Revert "xfrm: destroy xfrm_state synchronously on net exit path"") Reported-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6641a61fe0e2e89ae8c5 Tested-by: syzbot+6641a61fe0e2e89ae8c5@syzkaller.appspotmail.com Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysRevert "xfrm: destroy xfrm_state synchronously on net exit path"Sabrina Dubroca1-1/+1
[ Upstream commit 2a198bbec6913ae1c90ec963750003c6213668c7 ] This reverts commit f75a2804da391571563c4b6b29e7797787332673. With all states (whether user or kern) removed from the hashtables during deletion, there's no need for synchronous destruction of states. xfrm6_tunnel states still need to have been destroyed (which will be the case when its last user is deleted (not destroyed)) so that xfrm6_tunnel_free_spi removes it from the per-netns hashtable before the netns is destroyed. This has the benefit of skipping one synchronize_rcu per state (in __xfrm_state_destroy(sync=true)) when we exit a netns. Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
9 daysxfrm: delete x->tunnel as we delete xSabrina Dubroca2-1/+3
[ Upstream commit b441cf3f8c4b8576639d20c8eb4aa32917602ecd ] The ipcomp fallback tunnels currently get deleted (from the various lists and hashtables) as the last user state that needed that fallback is destroyed (not deleted). If a reference to that user state still exists, the fallback state will remain on the hashtables/lists, triggering the WARN in xfrm_state_fini. Because of those remaining references, the fix in commit f75a2804da39 ("xfrm: destroy xfrm_state synchronously on net exit path") is not complete. We recently fixed one such situation in TCP due to defered freeing of skbs (commit 9b6412e6979f ("tcp: drop secpath at the same time as we currently drop dst")). This can also happen due to IP reassembly: skbs with a secpath remain on the reassembly queue until netns destruction. If we can't guarantee that the queues are flushed by the time xfrm_state_fini runs, there may still be references to a (user) xfrm_state, preventing the timely deletion of the corresponding fallback state. Instead of chasing each instance of skbs holding a secpath one by one, this patch fixes the issue directly within xfrm, by deleting the fallback state as soon as the last user state depending on it has been deleted. Destruction will still happen when the final reference is dropped. A separate lockdep class for the fallback state is required since we're going to lock x->tunnel while x is locked. Fixes: 9d4139c76905 ("netns xfrm: per-netns xfrm_state_all list") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-01xfrm: Determine inner GSO type from packet inner protocolJianbo Liu1-2/+4
[ Upstream commit 61fafbee6cfed283c02a320896089f658fa67e56 ] The GSO segmentation functions for ESP tunnel mode (xfrm4_tunnel_gso_segment and xfrm6_tunnel_gso_segment) were determining the inner packet's L2 protocol type by checking the static x->inner_mode.family field from the xfrm state. This is unreliable. In tunnel mode, the state's actual inner family could be defined by x->inner_mode.family or by x->inner_mode_iaf.family. Checking only the former can lead to a mismatch with the actual packet being processed, causing GSO to create segments with the wrong L2 header type. This patch fixes the bug by deriving the inner mode directly from the packet's inner protocol stored in XFRM_MODE_SKB_CB(skb)->protocol. Instead of replicating the code, this patch modifies the xfrm_ip2inner_mode helper function. It now correctly returns &x->inner_mode if the selector family (x->sel.family) is already specified, thereby handling both specific and AF_UNSPEC cases appropriately. With this change, ESP GSO can use xfrm_ip2inner_mode to get the correct inner mode. It doesn't affect existing callers, as the updated logic now mirrors the checks they were already performing externally. Fixes: 26dbd66eab80 ("esp: choose the correct inner protocol for GSO on inter address family tunnels") Signed-off-by: Jianbo Liu <jianbol@nvidia.com> Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24espintcp: fix skb leaksSabrina Dubroca1-1/+3
[ Upstream commit 63c1f19a3be3169e51a5812d22a6d0c879414076 ] A few error paths are missing a kfree_skb. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> [ Minor context change fixed. ] Signed-off-by: Ruohan Lan <ruohanlan@aliyun.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24ipv6: np->rxpmtu race annotationEric Dumazet2-2/+2
[ Upstream commit 9fba1eb39e2f74d2002c5cbcf1d4435d37a4f752 ] Add READ_ONCE() annotations because np->rxpmtu can be changed while udpv6_recvmsg() and rawv6_recvmsg() read it. Since this is a very rarely used feature, and that udpv6_recvmsg() and rawv6_recvmsg() read np->rxopt anyway, change the test order so that np->rxpmtu does not need to be in a hot cache line. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250916160951.541279-4-edumazet@google.com Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24netfilter: nf_reject: don't reply to icmp error messagesFlorian Westphal1-0/+30
[ Upstream commit db99b2f2b3e2cd8227ac9990ca4a8a31a1e95e56 ] tcp reject code won't reply to a tcp reset. But the icmp reject 'netdev' family versions will reply to icmp dst-unreach errors, unlike icmp_send() and icmp6_send() which are used by the inet family implementation (and internally by the REJECT target). Check for the icmp(6) type and do not respond if its an unreachable error. Without this, something like 'ip protocol icmp reject', when used in a netdev chain attached to 'lo', cause a packet loop. Same for two hosts that both use such a rule: each error packet will be replied to. Such situation persist until the (bogus) rule is amended to ratelimit or checks the icmp type before the reject statement. As the inet versions don't do this make the netdev ones follow along. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24ipv6: Add sanity checks on ipv6_devconf.rpl_seg_enabledYue Haibing1-1/+3
[ Upstream commit 3d95261eeb74958cd496e1875684827dc5d028cc ] In ipv6_rpl_srh_rcv() we use min(net->ipv6.devconf_all->rpl_seg_enabled, idev->cnf.rpl_seg_enabled) is intended to return 0 when either value is zero, but if one of the values is negative it will in fact return non-zero. Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Link: https://patch.msgid.link/20250901123726.1972881-3-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24net: ipv6: fix field-spanning memcpy warning in AH outputCharalampos Mitrodimas1-19/+31
[ Upstream commit 2327a3d6f65ce2fe2634546dde4a25ef52296fec ] Fix field-spanning memcpy warnings in ah6_output() and ah6_output_done() where extension headers are copied to/from IPv6 address fields, triggering fortify-string warnings about writes beyond the 16-byte address fields. memcpy: detected field-spanning write (size 40) of single field "&top_iph->saddr" at net/ipv6/ah6.c:439 (size 16) WARNING: CPU: 0 PID: 8838 at net/ipv6/ah6.c:439 ah6_output+0xe7e/0x14e0 net/ipv6/ah6.c:439 The warnings are false positives as the extension headers are intentionally placed after the IPv6 header in memory. Fix by properly copying addresses and extension headers separately, and introduce helper functions to avoid code duplication. Reported-by: syzbot+01b0667934cdceb4451c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=01b0667934cdceb4451c Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-23net/ip6_tunnel: Prevent perpetual tunnel growthDmitry Safonov1-2/+1
[ Upstream commit 21f4d45eba0b2dcae5dbc9e5e0ad08735c993f16 ] Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too. While ipv4 tunnel headroom adjustment growth was limited in commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"), ipv6 tunnel yet increases the headroom without any ceiling. Reflect ipv4 tunnel headroom adjustment limit on ipv6 version. Credits to Francesco Ruggeri, who was originally debugging this issue and wrote local Arista-specific patch and a reproducer. Fixes: 8eb30be0352d ("ipv6: Create ip6_tnl_xmit") Cc: Florian Westphal <fw@strlen.de> Cc: Francesco Ruggeri <fruggeri05@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Link: https://patch.msgid.link/20251009-ip6_tunnel-headroom-v2-1-8e4dbd8f7e35@arista.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-25minmax: add a few more MIN_T/MAX_T usersLinus Torvalds1-1/+1
[ Upstream commit 4477b39c32fdc03363affef4b11d48391e6dc9ff ] Commit 3a7e02c040b1 ("minmax: avoid overly complicated constant expressions in VM code") added the simpler MIN_T/MAX_T macros in order to avoid some excessive expansion from the rather complicated regular min/max macros. The complexity of those macros stems from two issues: (a) trying to use them in situations that require a C constant expression (in static initializers and for array sizes) (b) the type sanity checking and MIN_T/MAX_T avoids both of these issues. Now, in the whole (long) discussion about all this, it was pointed out that the whole type sanity checking is entirely unnecessary for min_t/max_t which get a fixed type that the comparison is done in. But that still leaves min_t/max_t unnecessarily complicated due to worries about the C constant expression case. However, it turns out that there really aren't very many cases that use min_t/max_t for this, and we can just force-convert those. This does exactly that. Which in turn will then allow for much simpler implementations of min_t()/max_t(). All the usual "macros in all upper case will evaluate the arguments multiple times" rules apply. We should do all the same things for the regular min/max() vs MIN/MAX() cases, but that has the added complexity of various drivers defining their own local versions of MIN/MAX, so that needs another level of fixes first. Link: https://lore.kernel.org/all/b47fad1d0cf8449886ad148f8c013dae@AcuMS.aculab.com/ Cc: David Laight <David.Laight@aculab.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Eliav Farber <farbere@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-09icmp: fix icmp_ndo_send address translation for reply directionFabian Bläse1-2/+4
[ Upstream commit c6dd1aa2cbb72b33e0569f3e71d95792beab5042 ] The icmp_ndo_send function was originally introduced to ensure proper rate limiting when icmp_send is called by a network device driver, where the packet's source address may have already been transformed by SNAT. However, the original implementation only considers the IP_CT_DIR_ORIGINAL direction for SNAT and always replaced the packet's source address with that of the original-direction tuple. This causes two problems: 1. For SNAT: Reply-direction packets were incorrectly translated using the source address of the CT original direction, even though no translation is required. 2. For DNAT: Reply-direction packets were not handled at all. In DNAT, the original direction's destination is translated. Therefore, in the reply direction the source address must be set to the reply-direction source, so rate limiting works as intended. Fix this by using the connection direction to select the correct tuple for source address translation, and adjust the pre-checks to handle reply-direction packets in case of DNAT. Additionally, wrap the `ct->status` access in READ_ONCE(). This avoids possible KCSAN reports about concurrent updates to `ct->status`. Fixes: 0b41713b6066 ("icmp: introduce helper for nat'd source address in network device context") Signed-off-by: Fabian Bläse <fabian@blaese.de> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28netfilter: nf_reject: don't leak dst refcount for loopback packetsFlorian Westphal1-3/+2
[ Upstream commit 91a79b792204313153e1bdbbe5acbfc28903b3a5 ] recent patches to add a WARN() when replacing skb dst entry found an old bug: WARNING: include/linux/skbuff.h:1165 skb_dst_check_unset include/linux/skbuff.h:1164 [inline] WARNING: include/linux/skbuff.h:1165 skb_dst_set include/linux/skbuff.h:1210 [inline] WARNING: include/linux/skbuff.h:1165 nf_reject_fill_skb_dst+0x2a4/0x330 net/ipv4/netfilter/nf_reject_ipv4.c:234 [..] Call Trace: nf_send_unreach+0x17b/0x6e0 net/ipv4/netfilter/nf_reject_ipv4.c:325 nft_reject_inet_eval+0x4bc/0x690 net/netfilter/nft_reject_inet.c:27 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] .. This is because blamed commit forgot about loopback packets. Such packets already have a dst_entry attached, even at PRE_ROUTING stage. Instead of checking hook just check if the skb already has a route attached to it. Fixes: f53b9b0bdc59 ("netfilter: introduce support for reject at prerouting stage") Signed-off-by: Florian Westphal <fw@strlen.de> Link: https://patch.msgid.link/20250820123707.10671-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28ipv6: sr: validate HMAC algorithm ID in seg6_hmac_info_addMinhong He1-0/+3
[ Upstream commit 84967deee9d9870b15bc4c3acb50f1d401807902 ] The seg6_genl_sethmac() directly uses the algorithm ID provided by the userspace without verifying whether it is an HMAC algorithm supported by the system. If an unsupported HMAC algorithm ID is configured, packets using SRv6 HMAC will be dropped during encapsulation or decapsulation. Fixes: 4f4853dc1c9c ("ipv6: sr: implement API to control SR HMAC structure") Signed-off-by: Minhong He <heminhong@kylinos.cn> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20250815063845.85426-1-heminhong@kylinos.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28ipv6: sr: Fix MAC comparison to be constant-timeEric Biggers1-1/+2
commit a458b2902115b26a25d67393b12ddd57d1216aaa upstream. To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this. Fixes: bf355b8d2c30 ("ipv6: sr: add core files for SR HMAC support") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org> Reviewed-by: Andrea Mayer <andrea.mayer@uniroma2.it> Link: https://patch.msgid.link/20250818202724.15713-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28ipv6: mcast: Check inet6_dev->dead under idev->mc_lock in __ipv6_dev_mc_inc().Kuniyuki Iwashima2-10/+8
[ Upstream commit dbd40f318cf2f59759bd170c401adc20ba360a3e ] Since commit 63ed8de4be81 ("mld: add mc_lock for protecting per-interface mld data"), every multicast resource is protected by inet6_dev->mc_lock. RTNL is unnecessary in terms of protection but still needed for synchronisation between addrconf_ifdown() and __ipv6_dev_mc_inc(). Once we removed RTNL, there would be a race below, where we could add a multicast address to a dead inet6_dev. CPU1 CPU2 ==== ==== addrconf_ifdown() __ipv6_dev_mc_inc() if (idev->dead) <-- false dead = true return -ENODEV; ipv6_mc_destroy_dev() / ipv6_mc_down() mutex_lock(&idev->mc_lock) ... mutex_unlock(&idev->mc_lock) mutex_lock(&idev->mc_lock) ... mutex_unlock(&idev->mc_lock) The race window can be easily closed by checking inet6_dev->dead under inet6_dev->mc_lock in __ipv6_dev_mc_inc() as addrconf_ifdown() will acquire it after marking inet6_dev dead. Let's check inet6_dev->dead under mc_lock in __ipv6_dev_mc_inc(). Note that now __ipv6_dev_mc_inc() no longer depends on RTNL and we can remove ASSERT_RTNL() there and the RTNL comment above addrconf_join_solict(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250702230210.3115355-4-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15ipv6: reject malicious packets in ipv6_gso_segment()Eric Dumazet1-1/+3
[ Upstream commit d45cf1e7d7180256e17c9ce88e32e8061a7887fe ] syzbot was able to craft a packet with very long IPv6 extension headers leading to an overflow of skb->transport_header. This 16bit field has a limited range. Add skb_reset_transport_header_careful() helper and use it from ipv6_gso_segment() WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 skb_reset_transport_header include/linux/skbuff.h:3032 [inline] WARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151 Modules linked in: CPU: 0 UID: 0 PID: 5871 Comm: syz-executor211 Not tainted 6.16.0-rc6-syzkaller-g7abc678e3084 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:skb_reset_transport_header include/linux/skbuff.h:3032 [inline] RIP: 0010:ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151 Call Trace: <TASK> skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53 nsh_gso_segment+0x54a/0xe10 net/nsh/nsh.c:110 skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53 __skb_gso_segment+0x342/0x510 net/core/gso.c:124 skb_gso_segment include/net/gso.h:83 [inline] validate_xmit_skb+0x857/0x11b0 net/core/dev.c:3950 validate_xmit_skb_list+0x84/0x120 net/core/dev.c:4000 sch_direct_xmit+0xd3/0x4b0 net/sched/sch_generic.c:329 __dev_xmit_skb net/core/dev.c:4102 [inline] __dev_queue_xmit+0x17b6/0x3a70 net/core/dev.c:4679 Fixes: d1da932ed4ec ("ipv6: Separate ipv6 offload support") Reported-by: syzbot+af43e647fd835acc02df@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/688a1a05.050a0220.5d226.0008.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Dawid Osuchowski <dawid.osuchowski@linux.intel.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250730131738.3385939-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15ipv6: annotate data-races around rt->fib6_nsiblingsEric Dumazet2-9/+16
[ Upstream commit 31d7d67ba1274f42494256d52e86da80ed09f3cb ] rt->fib6_nsiblings can be read locklessly, add corresponding READ_ONCE() and WRITE_ONCE() annotations. Fixes: 66f5d6ce53e6 ("ipv6: replace rwlock with rcu and spinlock in fib6_table") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250725140725.3626540-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15ipv6: fix possible infinite loop in fib6_info_uses_dev()Eric Dumazet1-6/+11
[ Upstream commit f8d8ce1b515a0a6af72b30502670a406cfb75073 ] fib6_info_uses_dev() seems to rely on RCU without an explicit protection. Like the prior fix in rt6_nlmsg_size(), we need to make sure fib6_del_route() or fib6_add_rt2node() have not removed the anchor from the list, or we risk an infinite loop. Fixes: d9ccb18f83ea ("ipv6: Fix soft lockups in fib6_select_path under high next hop churn") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250725140725.3626540-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15ipv6: prevent infinite loop in rt6_nlmsg_size()Eric Dumazet2-18/+20
[ Upstream commit 54e6fe9dd3b0e7c481c2228782c9494d653546da ] While testing prior patch, I was able to trigger an infinite loop in rt6_nlmsg_size() in the following place: list_for_each_entry_rcu(sibling, &f6i->fib6_siblings, fib6_siblings) { rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len); } This is because fib6_del_route() and fib6_add_rt2node() uses list_del_rcu(), which can confuse rcu readers, because they might no longer see the head of the list. Restart the loop if f6i->fib6_nsiblings is zero. Fixes: d9ccb18f83ea ("ipv6: Fix soft lockups in fib6_select_path under high next hop churn") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250725140725.3626540-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15net: ipv6: ip6mr: Fix in/out netdev to pass to the FORWARD chainPetr Machata1-1/+2
[ Upstream commit 3365afd3abda5f6a54f4a822dad5c9314e94c3fc ] The netfilter hook is invoked with skb->dev for input netdevice, and vif_dev for output netdevice. However at the point of invocation, skb->dev is already set to vif_dev, and MR-forwarded packets are reported with in=out: # ip6tables -A FORWARD -j LOG --log-prefix '[forw]' # cd tools/testing/selftests/net/forwarding # ./router_multicast.sh # dmesg | fgrep '[forw]' [ 1670.248245] [forw]IN=v5 OUT=v5 [...] For reference, IPv4 MR code shows in and out as appropriate. Fix by caching skb->dev and using the updated value for output netdev. Fixes: 7bc570c8b4f7 ("[IPV6] MROUTE: Support multicast forwarding.") Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/3141ae8386fbe13fef4b793faa75e6bae58d798a.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-24ipv6: make addrconf_wq single threadedEric Dumazet1-1/+2
commit dfd2ee086a63c730022cb095576a8b3a5a752109 upstream. Both addrconf_verify_work() and addrconf_dad_work() acquire rtnl, there is no point trying to have one thread per cpu. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240201173031.3654257-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Brett A C Sheffield <bacs@librecast.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-24ipv6: mcast: Delay put pmc->idev in mld_del_delrec()Yue Haibing1-1/+1
[ Upstream commit ae3264a25a4635531264728859dbe9c659fad554 ] pmc->idev is still used in ip6_mc_clear_src(), so as mld_clear_delrec() does, the reference should be put after ip6_mc_clear_src() return. Fixes: 63ed8de4be81 ("mld: add mc_lock for protecting per-interface mld data") Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Link: https://patch.msgid.link/20250714141957.3301871-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-24rpl: Fix use-after-free in rpl_do_srh_inline().Kuniyuki Iwashima1-4/+4
[ Upstream commit b640daa2822a39ff76e70200cb2b7b892b896dce ] Running lwt_dst_cache_ref_loop.sh in selftest with KASAN triggers the splat below [0]. rpl_do_srh_inline() fetches ipv6_hdr(skb) and accesses it after skb_cow_head(), which is illegal as the header could be freed then. Let's fix it by making oldhdr to a local struct instead of a pointer. [0]: [root@fedora net]# ./lwt_dst_cache_ref_loop.sh ... TEST: rpl (input) [ 57.631529] ================================================================== BUG: KASAN: slab-use-after-free in rpl_do_srh_inline.isra.0 (net/ipv6/rpl_iptunnel.c:174) Read of size 40 at addr ffff888122bf96d8 by task ping6/1543 CPU: 50 UID: 0 PID: 1543 Comm: ping6 Not tainted 6.16.0-rc5-01302-gfadd1e6231b1 #23 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <IRQ> dump_stack_lvl (lib/dump_stack.c:122) print_report (mm/kasan/report.c:409 mm/kasan/report.c:521) kasan_report (mm/kasan/report.c:221 mm/kasan/report.c:636) kasan_check_range (mm/kasan/generic.c:175 (discriminator 1) mm/kasan/generic.c:189 (discriminator 1)) __asan_memmove (mm/kasan/shadow.c:94 (discriminator 2)) rpl_do_srh_inline.isra.0 (net/ipv6/rpl_iptunnel.c:174) rpl_input (net/ipv6/rpl_iptunnel.c:201 net/ipv6/rpl_iptunnel.c:282) lwtunnel_input (net/core/lwtunnel.c:459) ipv6_rcv (./include/net/dst.h:471 (discriminator 1) ./include/net/dst.h:469 (discriminator 1) net/ipv6/ip6_input.c:79 (discriminator 1) ./include/linux/netfilter.h:317 (discriminator 1) ./include/linux/netfilter.h:311 (discriminator 1) net/ipv6/ip6_input.c:311 (discriminator 1)) __netif_receive_skb_one_core (net/core/dev.c:5967) process_backlog (./include/linux/rcupdate.h:869 net/core/dev.c:6440) __napi_poll.constprop.0 (net/core/dev.c:7452) net_rx_action (net/core/dev.c:7518 net/core/dev.c:7643) handle_softirqs (kernel/softirq.c:579) do_softirq (kernel/softirq.c:480 (discriminator 20)) </IRQ> <TASK> __local_bh_enable_ip (kernel/softirq.c:407) __dev_queue_xmit (net/core/dev.c:4740) ip6_finish_output2 (./include/linux/netdevice.h:3358 ./include/net/neighbour.h:526 ./include/net/neighbour.h:540 net/ipv6/ip6_output.c:141) ip6_finish_output (net/ipv6/ip6_output.c:215 net/ipv6/ip6_output.c:226) ip6_output (./include/linux/netfilter.h:306 net/ipv6/ip6_output.c:248) ip6_send_skb (net/ipv6/ip6_output.c:1983) rawv6_sendmsg (net/ipv6/raw.c:588 net/ipv6/raw.c:918) __sys_sendto (net/socket.c:714 (discriminator 1) net/socket.c:729 (discriminator 1) net/socket.c:2228 (discriminator 1)) __x64_sys_sendto (net/socket.c:2231) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f68cffb2a06 Code: 5d e8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 75 19 83 e2 39 83 fa 08 75 11 e8 26 ff ff ff 66 0f 1f 44 00 00 48 8b 45 10 0f 05 <48> 8b 5d f8 c9 c3 0f 1f 40 00 f3 0f 1e fa 55 48 89 e5 48 83 ec 08 RSP: 002b:00007ffefb7c53d0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000564cd69f10a0 RCX: 00007f68cffb2a06 RDX: 0000000000000040 RSI: 0000564cd69f10a4 RDI: 0000000000000003 RBP: 00007ffefb7c53f0 R08: 0000564cd6a032ac R09: 000000000000001c R10: 0000000000000000 R11: 0000000000000202 R12: 0000564cd69f10a4 R13: 0000000000000040 R14: 00007ffefb7c66e0 R15: 0000564cd69f10a0 </TASK> Allocated by task 1543: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1)) __kasan_slab_alloc (mm/kasan/common.c:319 mm/kasan/common.c:345) kmem_cache_alloc_node_noprof (./include/linux/kasan.h:250 mm/slub.c:4148 mm/slub.c:4197 mm/slub.c:4249) kmalloc_reserve (net/core/skbuff.c:581 (discriminator 88)) __alloc_skb (net/core/skbuff.c:669) __ip6_append_data (net/ipv6/ip6_output.c:1672 (discriminator 1)) ip6_append_data (net/ipv6/ip6_output.c:1859) rawv6_sendmsg (net/ipv6/raw.c:911) __sys_sendto (net/socket.c:714 (discriminator 1) net/socket.c:729 (discriminator 1) net/socket.c:2228 (discriminator 1)) __x64_sys_sendto (net/socket.c:2231) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Freed by task 1543: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:60 (discriminator 1) mm/kasan/common.c:69 (discriminator 1)) kasan_save_free_info (mm/kasan/generic.c:579 (discriminator 1)) __kasan_slab_free (mm/kasan/common.c:271) kmem_cache_free (mm/slub.c:4643 (discriminator 3) mm/slub.c:4745 (discriminator 3)) pskb_expand_head (net/core/skbuff.c:2274) rpl_do_srh_inline.isra.0 (net/ipv6/rpl_iptunnel.c:158 (discriminator 1)) rpl_input (net/ipv6/rpl_iptunnel.c:201 net/ipv6/rpl_iptunnel.c:282) lwtunnel_input (net/core/lwtunnel.c:459) ipv6_rcv (./include/net/dst.h:471 (discriminator 1) ./include/net/dst.h:469 (discriminator 1) net/ipv6/ip6_input.c:79 (discriminator 1) ./include/linux/netfilter.h:317 (discriminator 1) ./include/linux/netfilter.h:311 (discriminator 1) net/ipv6/ip6_input.c:311 (discriminator 1)) __netif_receive_skb_one_core (net/core/dev.c:5967) process_backlog (./include/linux/rcupdate.h:869 net/core/dev.c:6440) __napi_poll.constprop.0 (net/core/dev.c:7452) net_rx_action (net/core/dev.c:7518 net/core/dev.c:7643) handle_softirqs (kernel/softirq.c:579) do_softirq (kernel/softirq.c:480 (discriminator 20)) __local_bh_enable_ip (kernel/softirq.c:407) __dev_queue_xmit (net/core/dev.c:4740) ip6_finish_output2 (./include/linux/netdevice.h:3358 ./include/net/neighbour.h:526 ./include/net/neighbour.h:540 net/ipv6/ip6_output.c:141) ip6_finish_output (net/ipv6/ip6_output.c:215 net/ipv6/ip6_output.c:226) ip6_output (./include/linux/netfilter.h:306 net/ipv6/ip6_output.c:248) ip6_send_skb (net/ipv6/ip6_output.c:1983) rawv6_sendmsg (net/ipv6/raw.c:588 net/ipv6/raw.c:918) __sys_sendto (net/socket.c:714 (discriminator 1) net/socket.c:729 (discriminator 1) net/socket.c:2228 (discriminator 1)) __x64_sys_sendto (net/socket.c:2231) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) The buggy address belongs to the object at ffff888122bf96c0 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 24 bytes inside of freed 704-byte region [ffff888122bf96c0, ffff888122bf9980) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x122bf8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff888101fc0a00 ffffea000464dc00 0000000000000002 raw: 0000000000000000 0000000080270027 00000000f5000000 0000000000000000 head: 0200000000000040 ffff888101fc0a00 ffffea000464dc00 0000000000000002 head: 0000000000000000 0000000080270027 00000000f5000000 0000000000000000 head: 0200000000000003 ffffea00048afe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888122bf9580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888122bf9600: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888122bf9680: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ^ ffff888122bf9700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888122bf9780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: a7a29f9c361f8 ("net: ipv6: add rpl sr tunnel") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-17gre: Fix IPv6 multicast route creation.Guillaume Nault1-7/+2
commit 4e914ef063de40397e25a025c70d9737a9e45a8c upstream. Use addrconf_add_dev() instead of ipv6_find_idev() in addrconf_gre_config() so that we don't just get the inet6_dev, but also install the default ff00::/8 multicast route. Before commit 3e6a0243ff00 ("gre: Fix again IPv6 link-local address generation."), the multicast route was created at the end of the function by addrconf_add_mroute(). But this code path is now only taken in one particular case (gre devices not bound to a local IP address and in EUI64 mode). For all other cases, the function exits early and addrconf_add_mroute() is not called anymore. Using addrconf_add_dev() instead of ipv6_find_idev() in addrconf_gre_config(), fixes the problem as it will create the default multicast route for all gre devices. This also brings addrconf_gre_config() a bit closer to the normal netdevice IPv6 configuration code (addrconf_dev_config()). Cc: stable@vger.kernel.org Fixes: 3e6a0243ff00 ("gre: Fix again IPv6 link-local address generation.") Reported-by: Aiden Yang <ling@moedove.com> Closes: https://lore.kernel.org/netdev/CANR=AhRM7YHHXVxJ4DmrTNMeuEOY87K2mLmo9KMed1JMr20p6g@mail.gmail.com/ Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Gary Guo <gary@garyguo.net> Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/027a923dcb550ad115e6d93ee8bb7d310378bd01.1752070620.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-06Revert "ipv6: save dontfrag in cork"Brett A C Sheffield (Librecast)1-5/+4
This reverts commit 8ebf2709fe4dcd0a1b7b95bf61e529ddcd3cdf51 which is commit a18dfa9925b9ef6107ea3aa5814ca3c704d34a8a upstream. A regression was introduced when backporting this to the stable kernels without applying previous commits in this series. When sending IPv6 UDP packets larger than MTU, EMSGSIZE was returned instead of fragmenting the packets as expected. As there is no compelling reason for this commit to be present in the stable kernels it should be reverted. Signed-off-by: Brett A C Sheffield <bacs@librecast.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-27calipso: Fix null-ptr-deref in calipso_req_{set,del}attr().Kuniyuki Iwashima1-0/+8
[ Upstream commit 10876da918fa1aec0227fb4c67647513447f53a9 ] syzkaller reported a null-ptr-deref in sock_omalloc() while allocating a CALIPSO option. [0] The NULL is of struct sock, which was fetched by sk_to_full_sk() in calipso_req_setattr(). Since commit a1a5344ddbe8 ("tcp: avoid two atomic ops for syncookies"), reqsk->rsk_listener could be NULL when SYN Cookie is returned to its client, as hinted by the leading SYN Cookie log. Here are 3 options to fix the bug: 1) Return 0 in calipso_req_setattr() 2) Return an error in calipso_req_setattr() 3) Alaways set rsk_listener 1) is no go as it bypasses LSM, but 2) effectively disables SYN Cookie for CALIPSO. 3) is also no go as there have been many efforts to reduce atomic ops and make TCP robust against DDoS. See also commit 3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt under synflood"). As of the blamed commit, SYN Cookie already did not need refcounting, and no one has stumbled on the bug for 9 years, so no CALIPSO user will care about SYN Cookie. Let's return an error in calipso_req_setattr() and calipso_req_delattr() in the SYN Cookie case. This can be reproduced by [1] on Fedora and now connect() of nc times out. [0]: TCP: request_sock_TCPv6: Possible SYN flooding on port [::]:20002. Sending cookies. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 3 UID: 0 PID: 12262 Comm: syz.1.2611 Not tainted 6.14.0 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_pnet include/net/net_namespace.h:406 [inline] RIP: 0010:sock_net include/net/sock.h:655 [inline] RIP: 0010:sock_kmalloc+0x35/0x170 net/core/sock.c:2806 Code: 89 d5 41 54 55 89 f5 53 48 89 fb e8 25 e3 c6 fd e8 f0 91 e3 00 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 26 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffff88811af89038 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888105266400 RDX: 0000000000000006 RSI: ffff88800c890000 RDI: 0000000000000030 RBP: 0000000000000050 R08: 0000000000000000 R09: ffff88810526640e R10: ffffed1020a4cc81 R11: ffff88810526640f R12: 0000000000000000 R13: 0000000000000820 R14: ffff888105266400 R15: 0000000000000050 FS: 00007f0653a07640(0000) GS:ffff88811af80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f863ba096f4 CR3: 00000000163c0005 CR4: 0000000000770ef0 PKRU: 80000000 Call Trace: <IRQ> ipv6_renew_options+0x279/0x950 net/ipv6/exthdrs.c:1288 calipso_req_setattr+0x181/0x340 net/ipv6/calipso.c:1204 calipso_req_setattr+0x56/0x80 net/netlabel/netlabel_calipso.c:597 netlbl_req_setattr+0x18a/0x440 net/netlabel/netlabel_kapi.c:1249 selinux_netlbl_inet_conn_request+0x1fb/0x320 security/selinux/netlabel.c:342 selinux_inet_conn_request+0x1eb/0x2c0 security/selinux/hooks.c:5551 security_inet_conn_request+0x50/0xa0 security/security.c:4945 tcp_v6_route_req+0x22c/0x550 net/ipv6/tcp_ipv6.c:825 tcp_conn_request+0xec8/0x2b70 net/ipv4/tcp_input.c:7275 tcp_v6_conn_request+0x1e3/0x440 net/ipv6/tcp_ipv6.c:1328 tcp_rcv_state_process+0xafa/0x52b0 net/ipv4/tcp_input.c:6781 tcp_v6_do_rcv+0x8a6/0x1a40 net/ipv6/tcp_ipv6.c:1667 tcp_v6_rcv+0x505e/0x5b50 net/ipv6/tcp_ipv6.c:1904 ip6_protocol_deliver_rcu+0x17c/0x1da0 net/ipv6/ip6_input.c:436 ip6_input_finish+0x103/0x180 net/ipv6/ip6_input.c:480 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_input+0x13c/0x6b0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] ip6_rcv_finish+0xb6/0x490 net/ipv6/ip6_input.c:69 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ipv6_rcv+0xf9/0x490 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x12e/0x1f0 net/core/dev.c:5896 __netif_receive_skb+0x1d/0x170 net/core/dev.c:6009 process_backlog+0x41e/0x13b0 net/core/dev.c:6357 __napi_poll+0xbd/0x710 net/core/dev.c:7191 napi_poll net/core/dev.c:7260 [inline] net_rx_action+0x9de/0xde0 net/core/dev.c:7382 handle_softirqs+0x19a/0x770 kernel/softirq.c:561 do_softirq.part.0+0x36/0x70 kernel/softirq.c:462 </IRQ> <TASK> do_softirq arch/x86/include/asm/preempt.h:26 [inline] __local_bh_enable_ip+0xf1/0x110 kernel/softirq.c:389 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] __dev_queue_xmit+0xc2a/0x3c40 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3313 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip6_finish_output2+0xd69/0x1f80 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline] ip6_finish_output+0x5dc/0xd60 net/ipv6/ip6_output.c:226 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip6_output+0x24b/0x8d0 net/ipv6/ip6_output.c:247 dst_output include/net/dst.h:459 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_xmit+0xbbc/0x20d0 net/ipv6/ip6_output.c:366 inet6_csk_xmit+0x39a/0x720 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1a7b/0x3b40 net/ipv4/tcp_output.c:1471 tcp_transmit_skb net/ipv4/tcp_output.c:1489 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:4059 [inline] tcp_connect+0x1c0c/0x4510 net/ipv4/tcp_output.c:4148 tcp_v6_connect+0x156c/0x2080 net/ipv6/tcp_ipv6.c:333 __inet_stream_connect+0x3a7/0xed0 net/ipv4/af_inet.c:677 tcp_sendmsg_fastopen+0x3e2/0x710 net/ipv4/tcp.c:1039 tcp_sendmsg_locked+0x1e82/0x3570 net/ipv4/tcp.c:1091 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1358 inet6_sendmsg+0xb9/0x150 net/ipv6/af_inet6.c:659 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0xf4/0x2a0 net/socket.c:733 __sys_sendto+0x29a/0x390 net/socket.c:2187 __do_sys_sendto net/socket.c:2194 [inline] __se_sys_sendto net/socket.c:2190 [inline] __x64_sys_sendto+0xe1/0x1c0 net/socket.c:2190 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc3/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f06553c47ed Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0653a06fc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f0655605fa0 RCX: 00007f06553c47ed RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000b RBP: 00007f065545db38 R08: 0000200000000140 R09: 000000000000001c R10: f7384d4ea84b01bd R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0655605fac R14: 00007f0655606038 R15: 00007f06539e7000 </TASK> Modules linked in: [1]: dnf install -y selinux-policy-targeted policycoreutils netlabel_tools procps-ng nmap-ncat mount -t selinuxfs none /sys/fs/selinux load_policy netlabelctl calipso add pass doi:1 netlabelctl map del default netlabelctl map add default address:::1 protocol:calipso,1 sysctl net.ipv4.tcp_syncookies=2 nc -l ::1 80 & nc ::1 80 Fixes: e1adea927080 ("calipso: Allow request sockets to be relabelled by the lsm.") Reported-by: syzkaller <syzkaller@googlegroups.com> Reported-by: John Cheung <john.cs.hey@gmail.com> Closes: https://lore.kernel.org/netdev/CAP=Rh=MvfhrGADy+-WJiftV2_WzMH4VEhEFmeT28qY+4yxNu4w@mail.gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://patch.msgid.link/20250617224125.17299-1-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27net: Fix checksum update for ILA adj-transportPaul Chaignon1-3/+3
commit 6043b794c7668c19dabc4a93c75b924a19474d59 upstream. During ILA address translations, the L4 checksums can be handled in different ways. One of them, adj-transport, consist in parsing the transport layer and updating any found checksum. This logic relies on inet_proto_csum_replace_by_diff and produces an incorrect skb->csum when in state CHECKSUM_COMPLETE. This bug can be reproduced with a simple ILA to SIR mapping, assuming packets are received with CHECKSUM_COMPLETE: $ ip a show dev eth0 14: eth0@if15: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 62:ae:35:9e:0f:8d brd ff:ff:ff:ff:ff:ff link-netnsid 0 inet6 3333:0:0:1::c078/64 scope global valid_lft forever preferred_lft forever inet6 fd00:10:244:1::c078/128 scope global nodad valid_lft forever preferred_lft forever inet6 fe80::60ae:35ff:fe9e:f8d/64 scope link proto kernel_ll valid_lft forever preferred_lft forever $ ip ila add loc_match fd00:10:244:1 loc 3333:0:0:1 \ csum-mode adj-transport ident-type luid dev eth0 Then I hit [fd00:10:244:1::c078]:8000 with a server listening only on [3333:0:0:1::c078]:8000. With the bug, the SYN packet is dropped with SKB_DROP_REASON_TCP_CSUM after inet_proto_csum_replace_by_diff changed skb->csum. The translation and drop are visible on pwru [1] traces: IFACE TUPLE FUNC eth0:9 [fd00:10:244:3::3d8]:51420->[fd00:10:244:1::c078]:8000(tcp) ipv6_rcv eth0:9 [fd00:10:244:3::3d8]:51420->[fd00:10:244:1::c078]:8000(tcp) ip6_rcv_core eth0:9 [fd00:10:244:3::3d8]:51420->[fd00:10:244:1::c078]:8000(tcp) nf_hook_slow eth0:9 [fd00:10:244:3::3d8]:51420->[fd00:10:244:1::c078]:8000(tcp) inet_proto_csum_replace_by_diff eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) tcp_v6_early_demux eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ip6_route_input eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ip6_input eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ip6_input_finish eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ip6_protocol_deliver_rcu eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) raw6_local_deliver eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) ipv6_raw_deliver eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) tcp_v6_rcv eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) __skb_checksum_complete eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) kfree_skb_reason(SKB_DROP_REASON_TCP_CSUM) eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) skb_release_head_state eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) skb_release_data eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) skb_free_head eth0:9 [fd00:10:244:3::3d8]:51420->[3333:0:0:1::c078]:8000(tcp) kfree_skbmem This is happening because inet_proto_csum_replace_by_diff is updating skb->csum when it shouldn't. The L4 checksum is updated such that it "cancels" the IPv6 address change in terms of checksum computation, so the impact on skb->csum is null. Note this would be different for an IPv4 packet since three fields would be updated: the IPv4 address, the IP checksum, and the L4 checksum. Two would cancel each other and skb->csum would still need to be updated to take the L4 checksum change into account. This patch fixes it by passing an ipv6 flag to inet_proto_csum_replace_by_diff, to skip the skb->csum update if we're in the IPv6 case. Note the behavior of the only other user of inet_proto_csum_replace_by_diff, the BPF subsystem, is left as is in this patch and fixed in the subsequent patch. With the fix, using the reproduction from above, I can confirm skb->csum is not touched by inet_proto_csum_replace_by_diff and the TCP SYN proceeds to the application after the ILA translation. Link: https://github.com/cilium/pwru [1] Fixes: 65d7ab8de582 ("net: Identifier Locator Addressing module") Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://patch.msgid.link/b5539869e3550d46068504feb02d37653d939c0b.1748509484.git.paul.chaignon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-19seg6: Fix validation of nexthop addressesIdo Schimmel1-4/+2
[ Upstream commit 7632fedb266d93ed0ed9f487133e6c6314a9b2d1 ] The kernel currently validates that the length of the provided nexthop address does not exceed the specified length. This can lead to the kernel reading uninitialized memory if user space provided a shorter length than the specified one. Fix by validating that the provided length exactly matches the specified one. Fixes: d1df6fd8a1d2 ("ipv6: sr: define core operations for seg6local lightweight tunnel") Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250604113252.371528-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-19netfilter: nf_tables: nft_fib_ipv6: fix VRF ipv4/ipv6 result discrepancyFlorian Westphal1-4/+9
[ Upstream commit 8b53f46eb430fe5b42d485873b85331d2de2c469 ] With a VRF, ipv4 and ipv6 FIB expression behave differently. fib daddr . iif oif Will return the input interface name for ipv4, but the real device for ipv6. Example: If VRF device name is tvrf and real (incoming) device is veth0. First round is ok, both ipv4 and ipv6 will yield 'veth0'. But in the second round (incoming device will be set to "tvrf"), ipv4 will yield "tvrf" whereas ipv6 returns "veth0" for the second round too. This makes ipv6 behave like ipv4. A followup patch will add a test case for this, without this change it will fail with: get element inet t fibif6iif { tvrf . dead:1::99 . tvrf } ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ FAIL: did not find tvrf . dead:1::99 . tvrf in fibif6iif Alternatively we could either not do anything at all or change ipv4 to also return the lower/real device, however, nft (userspace) doc says "iif: if fib lookup provides a route then check its output interface is identical to the packets input interface." which is what the nft fib ipv4 behaviour is. Fixes: f6d0cbcf09c5 ("netfilter: nf_tables: add fib expression") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-19netfilter: bridge: Move specific fragmented packet to slow_path instead of ↵Huajian Yang1-6/+6
dropping it [ Upstream commit aa04c6f45b9224b949aa35d4fa5f8d0ba07b23d4 ] The config NF_CONNTRACK_BRIDGE will change the bridge forwarding for fragmented packets. The original bridge does not know that it is a fragmented packet and forwards it directly, after NF_CONNTRACK_BRIDGE is enabled, function nf_br_ip_fragment and br_ip6_fragment will check the headroom. In original br_forward, insufficient headroom of skb may indeed exist, but there's still a way to save the skb in the device driver after dev_queue_xmit.So droping the skb will change the original bridge forwarding in some cases. Fixes: 3c171f496ef5 ("netfilter: bridge: add connection tracking system") Signed-off-by: Huajian Yang <huajianyang@asrmicro.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04espintcp: remove encap socket caching to avoid reference leakSabrina Dubroca1-45/+4
[ Upstream commit 028363685bd0b7a19b4a820f82dd905b1dc83999 ] The current scheme for caching the encap socket can lead to reference leaks when we try to delete the netns. The reference chain is: xfrm_state -> enacp_sk -> netns Since the encap socket is a userspace socket, it holds a reference on the netns. If we delete the espintcp state (through flush or individual delete) before removing the netns, the reference on the socket is dropped and the netns is correctly deleted. Otherwise, the netns may not be reachable anymore (if all processes within the ns have terminated), so we cannot delete the xfrm state to drop its reference on the socket. This patch results in a small (~2% in my tests) performance regression. A GC-type mechanism could be added for the socket cache, to clear references if the state hasn't been used "recently", but it's a lot more complex than just not caching the socket. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04ip: fib_rules: Fetch net from fib_rule in fib[46]_rule_configure().Kuniyuki Iwashima1-2/+2
[ Upstream commit 5a1ccffd30a08f5a2428cd5fbb3ab03e8eb6c66d ] The following patch will not set skb->sk from VRF path. Let's fetch net from fib_rule->fr_net instead of sock_net(skb->sk) in fib[46]_rule_configure(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20250207072502.87775-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-04ipv6: save dontfrag in corkWillem de Bruijn1-4/+5
[ Upstream commit a18dfa9925b9ef6107ea3aa5814ca3c704d34a8a ] When spanning datagram construction over multiple send calls using MSG_MORE, per datagram settings are configured on the first send. That is when ip(6)_setup_cork stores these settings for subsequent use in __ip(6)_append_data and others. The only flag that escaped this was dontfrag. As a result, a datagram could be constructed with df=0 on the first sendmsg, but df=1 on a next. Which is what cmsg_ip.sh does in an upcoming MSG_MORE test in the "diff" scenario. Changing datagram conditions in the middle of constructing an skb makes this already complex code path even more convoluted. It is here unintentional. Bring this flag in line with expected sockopt/cmsg behavior. And stop passing ipc6 to __ip6_append_data, to avoid such issues in the future. This is already the case for __ip_append_data. inet6_cork had a 6 byte hole, so the 1B flag has no impact. Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250307033620.411611-3-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-18gre: Fix again IPv6 link-local address generation.Guillaume Nault1-6/+9
[ Upstream commit 3e6a0243ff002ddbd7ee18a8974ae61d2e6ed00d ] Use addrconf_addr_gen() to generate IPv6 link-local addresses on GRE devices in most cases and fall back to using add_v4_addrs() only in case the GRE configuration is incompatible with addrconf_addr_gen(). GRE used to use addrconf_addr_gen() until commit e5dd729460ca ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address") restricted this use to gretap and ip6gretap devices, and created add_v4_addrs() (borrowed from SIT) for non-Ethernet GRE ones. The original problem came when commit 9af28511be10 ("addrconf: refuse isatap eui64 for INADDR_ANY") made __ipv6_isatap_ifid() fail when its addr parameter was 0. The commit says that this would create an invalid address, however, I couldn't find any RFC saying that the generated interface identifier would be wrong. Anyway, since gre over IPv4 devices pass their local tunnel address to __ipv6_isatap_ifid(), that commit broke their IPv6 link-local address generation when the local address was unspecified. Then commit e5dd729460ca ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address") tried to fix that case by defining add_v4_addrs() and calling it to generate the IPv6 link-local address instead of using addrconf_addr_gen() (apart for gretap and ip6gretap devices, which would still use the regular addrconf_addr_gen(), since they have a MAC address). That broke several use cases because add_v4_addrs() isn't properly integrated into the rest of IPv6 Neighbor Discovery code. Several of these shortcomings have been fixed over time, but add_v4_addrs() remains broken on several aspects. In particular, it doesn't send any Router Sollicitations, so the SLAAC process doesn't start until the interface receives a Router Advertisement. Also, add_v4_addrs() mostly ignores the address generation mode of the interface (/proc/sys/net/ipv6/conf/*/addr_gen_mode), thus breaking the IN6_ADDR_GEN_MODE_RANDOM and IN6_ADDR_GEN_MODE_STABLE_PRIVACY cases. Fix the situation by using add_v4_addrs() only in the specific scenario where the normal method would fail. That is, for interfaces that have all of the following characteristics: * run over IPv4, * transport IP packets directly, not Ethernet (that is, not gretap interfaces), * tunnel endpoint is INADDR_ANY (that is, 0), * device address generation mode is EUI64. In all other cases, revert back to the regular addrconf_addr_gen(). Also, remove the special case for ip6gre interfaces in add_v4_addrs(), since ip6gre devices now always use addrconf_addr_gen() instead. Note: This patch was originally applied as commit 183185a18ff9 ("gre: Fix IPv6 link-local address generation."). However, it was then reverted by commit fc486c2d060f ("Revert "gre: Fix IPv6 link-local address generation."") because it uncovered another bug that ended up breaking net/forwarding/ip6gre_custom_multipath_hash.sh. That other bug has now been fixed by commit 4d0ab3a6885e ("ipv6: Start path selection from the first nexthop"). Therefore we can now revive this GRE patch (no changes since original commit 183185a18ff9 ("gre: Fix IPv6 link-local address generation."). Fixes: e5dd729460ca ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address") Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/a88cc5c4811af36007645d610c95102dccb360a6.1746225214.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-09net: Rename mono_delivery_time to tstamp_type for scalabiltyAbhishek Chauhan5-9/+9
[ Upstream commit 4d25ca2d6801cfcf26f7f39c561611ba5be99bf8 ] mono_delivery_time was added to check if skb->tstamp has delivery time in mono clock base (i.e. EDT) otherwise skb->tstamp has timestamp in ingress and delivery_time at egress. Renaming the bitfield from mono_delivery_time to tstamp_type is for extensibilty for other timestamps such as userspace timestamp (i.e. SO_TXTIME) set via sock opts. As we are renaming the mono_delivery_time to tstamp_type, it makes sense to start assigning tstamp_type based on enum defined in this commit. Earlier we used bool arg flag to check if the tstamp is mono in function skb_set_delivery_time, Now the signature of the functions accepts tstamp_type to distinguish between mono and real time. Also skb_set_delivery_type_by_clockid is a new function which accepts clockid to determine the tstamp_type. In future tstamp_type:1 can be extended to support userspace timestamp by increasing the bitfield. Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20240509211834.3235191-2-quic_abchauha@quicinc.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Stable-dep-of: 3908feb1bd7f ("Bluetooth: L2CAP: copy RX timestamp to new fragments") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-25ipv6: Align behavior across nexthops during path selectionIdo Schimmel1-4/+4
[ Upstream commit 6933cd4714861eea6848f18396a119d741f25fc3 ] A nexthop is only chosen when the calculated multipath hash falls in the nexthop's hash region (i.e., the hash is smaller than the nexthop's hash threshold) and when the nexthop is assigned a non-negative score by rt6_score_route(). Commit 4d0ab3a6885e ("ipv6: Start path selection from the first nexthop") introduced an unintentional difference between the first nexthop and the rest when the score is negative. When the first nexthop matches, but has a negative score, the code will currently evaluate subsequent nexthops until one is found with a non-negative score. On the other hand, when a different nexthop matches, but has a negative score, the code will fallback to the nexthop with which the selection started ('match'). Align the behavior across all nexthops and fallback to 'match' when the first nexthop matches, but has a negative score. Fixes: 3d709f69a3e7 ("ipv6: Use hash-threshold instead of modulo-N") Fixes: 4d0ab3a6885e ("ipv6: Start path selection from the first nexthop") Reported-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Closes: https://lore.kernel.org/netdev/67efef607bc41_1ddca82948c@willemb.c.googlers.com.notmuch/ Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250408084316.243559-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10ipv6: Do not consider link down nexthops in path selectionIdo Schimmel1-2/+4
[ Upstream commit 8b8e0dd357165e0258d9f9cdab5366720ed2f619 ] Nexthops whose link is down are not supposed to be considered during path selection when the "ignore_routes_with_linkdown" sysctl is set. This is done by assigning them a negative region boundary. However, when comparing the computed hash (unsigned) with the region boundary (signed), the negative region boundary is treated as unsigned, resulting in incorrect nexthop selection. Fix by treating the computed hash as signed. Note that the computed hash is always in range of [0, 2^31 - 1]. Fixes: 3d709f69a3e7 ("ipv6: Use hash-threshold instead of modulo-N") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250402114224.293392-3-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10ipv6: Start path selection from the first nexthopIdo Schimmel1-3/+35
[ Upstream commit 4d0ab3a6885e3e9040310a8d8f54503366083626 ] Cited commit transitioned IPv6 path selection to use hash-threshold instead of modulo-N. With hash-threshold, each nexthop is assigned a region boundary in the multipath hash function's output space and a nexthop is chosen if the calculated hash is smaller than the nexthop's region boundary. Hash-threshold does not work correctly if path selection does not start with the first nexthop. For example, if fib6_select_path() is always passed the last nexthop in the group, then it will always be chosen because its region boundary covers the entire hash function's output space. Fix this by starting the selection process from the first nexthop and do not consider nexthops for which rt6_score_route() provided a negative score. Fixes: 3d709f69a3e7 ("ipv6: Use hash-threshold instead of modulo-N") Reported-by: Stanislav Fomichev <stfomichev@gmail.com> Closes: https://lore.kernel.org/netdev/Z9RIyKZDNoka53EO@mini-arch/ Signed-off-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20250402114224.293392-2-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10ipv6: fix omitted netlink attributes when using RTEXT_FILTER_SKIP_STATSFernando Fernandez Mancera1-12/+25
[ Upstream commit 7ac6ea4a3e0898db76aecccd68fb2c403eb7d24e ] Using RTEXT_FILTER_SKIP_STATS is incorrectly skipping non-stats IPv6 netlink attributes on link dump. This causes issues on userspace tools, e.g iproute2 is not rendering address generation mode as it should due to missing netlink attribute. Move the filling of IFLA_INET6_STATS and IFLA_INET6_ICMP6STATS to a helper function guarded by a flag check to avoid hitting the same situation in the future. Fixes: d5566fd72ec1 ("rtnetlink: RTEXT_FILTER_SKIP_STATS support to avoid dumping inet/inet6 stats") Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250402121751.3108-1-ffmancera@riseup.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10netlabel: Fix NULL pointer exception caused by CALIPSO on IPv4 socketsDebin Zhu1-3/+18
[ Upstream commit 078aabd567de3d63d37d7673f714e309d369e6e2 ] When calling netlbl_conn_setattr(), addr->sa_family is used to determine the function behavior. If sk is an IPv4 socket, but the connect function is called with an IPv6 address, the function calipso_sock_setattr() is triggered. Inside this function, the following code is executed: sk_fullsock(__sk) ? inet_sk(__sk)->pinet6 : NULL; Since sk is an IPv4 socket, pinet6 is NULL, leading to a null pointer dereference. This patch fixes the issue by checking if inet6_sk(sk) returns a NULL pointer before accessing pinet6. Signed-off-by: Debin Zhu <mowenroot@163.com> Signed-off-by: Bitao Ouyang <1985755126@qq.com> Acked-by: Paul Moore <paul@paul-moore.com> Fixes: ceba1832b1b2 ("calipso: Set the calipso socket label to match the secattr.") Link: https://patch.msgid.link/20250401124018.4763-1-mowenroot@163.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-07netfilter: socket: Lookup orig tuple for IPv6 SNATMaxim Mikityanskiy1-0/+23
commit 932b32ffd7604fb00b5c57e239a3cc4d901ccf6e upstream. nf_sk_lookup_slow_v4 does the conntrack lookup for IPv4 packets to restore the original 5-tuple in case of SNAT, to be able to find the right socket (if any). Then socket_match() can correctly check whether the socket was transparent. However, the IPv6 counterpart (nf_sk_lookup_slow_v6) lacks this conntrack lookup, making xt_socket fail to match on the socket when the packet was SNATed. Add the same logic to nf_sk_lookup_slow_v6. IPv6 SNAT is used in Kubernetes clusters for pod-to-world packets, as pods' addresses are in the fd00::/8 ULA subnet and need to be replaced with the node's external address. Cilium leverages Envoy to enforce L7 policies, and Envoy uses transparent sockets. Cilium inserts an iptables prerouting rule that matches on `-m socket --transparent` and redirects the packets to localhost, but it fails to match SNATed IPv6 packets due to that missing conntrack lookup. Closes: https://github.com/cilium/cilium/issues/37932 Fixes: eb31628e37a0 ("netfilter: nf_tables: Add support for IPv6 NAT") Signed-off-by: Maxim Mikityanskiy <maxim@isovalent.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-28Revert "gre: Fix IPv6 link-local address generation."Guillaume Nault1-9/+6
[ Upstream commit fc486c2d060f67d672ddad81724f7c8a4d329570 ] This reverts commit 183185a18ff96751db52a46ccf93fff3a1f42815. This patch broke net/forwarding/ip6gre_custom_multipath_hash.sh in some circumstances (https://lore.kernel.org/netdev/Z9RIyKZDNoka53EO@mini-arch/). Let's revert it while the problem is being investigated. Fixes: 183185a18ff9 ("gre: Fix IPv6 link-local address generation.") Signed-off-by: Guillaume Nault <gnault@redhat.com> Link: https://patch.msgid.link/8b1ce738eb15dd841aab9ef888640cab4f6ccfea.1742418408.git.gnault@redhat.com Acked-by: Stanislav Fomichev <sdf@fomichev.me> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
generated by cgit v1.2.3 (git 2.39.0) at 2026-01-21 04:35:40 +0300