kernel/linux.git/net/ipv4/netfilter, branch v5.10.257

netfilter: nf_reject: don't leak dst refcount for loopback packets

2025-08-28T14:22:59+00:00

[ 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 Link: https://patch.msgid.link/20250820123707.10671-1-fw@strlen.de Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netfilter: nft_reject_inet: allow to use reject from inet ingress

2025-08-28T14:22:59+00:00

[ Upstream commit 117ca1f8920cf4087bf82f44bd2a51b49d6aae63 ] Enhance validation to support for reject from inet ingress chains. Note that, reject from inet ingress and netdev ingress differ. Reject packets from inet ingress are sent through ip_local_out() since inet reject emulates the IP layer receive path. So the reject packet follows to classic IP output and postrouting paths. The reject action from netdev ingress assumes the packet not yet entered the IP layer, so the reject packet is sent through dev_queue_xmit(). Therefore, reject packets from netdev ingress do not follow the classic IP output and postrouting paths. Signed-off-by: Pablo Neira Ayuso Stable-dep-of: 91a79b792204 ("netfilter: nf_reject: don't leak dst refcount for loopback packets") Signed-off-by: Sasha Levin

netfilter: fib: check correct rtable in vrf setups

2024-10-17T13:08:36+00:00

[ Upstream commit 05ef7055debc804e8083737402127975e7244fc4 ] We need to init l3mdev unconditionally, else main routing table is searched and incorrect result is returned unless strict (iif keyword) matching is requested. Next patch adds a selftest for this. Fixes: 2a8a7c0eaa87 ("netfilter: nft_fib: Fix for rpath check with VRF devices") Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1761 Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: rpfilter/fib: Set ->flowic_uid correctly for user namespaces.

2024-10-17T13:08:36+00:00

[ Upstream commit 1fcc064b305a1aadeff0d4bff961094d27660acd ] Currently netfilter's rpfilter and fib modules implicitely initialise ->flowic_uid with 0. This is normally the root UID. However, this isn't the case in user namespaces, where user ID 0 is mapped to a different kernel UID. By initialising ->flowic_uid with sock_net_uid(), we get the root UID of the user namespace, thus keeping the same behaviour whether or not we're running in a user namepspace. Note, this is similar to commit 8bcfd0925ef1 ("ipv4: add missing initialization for flowi4_uid"), which fixed the rp_filter sysctl. Fixes: 622ec2c9d524 ("net: core: add UID to flows, rules, and routes") Signed-off-by: Guillaume Nault Signed-off-by: Pablo Neira Ayuso Stable-dep-of: 05ef7055debc ("netfilter: fib: check correct rtable in vrf setups") Signed-off-by: Sasha Levin

netfilter: rpfilter/fib: Populate flowic_l3mdev field

2024-10-17T13:08:36+00:00

[ Upstream commit acc641ab95b66b813c1ce856c377a2bbe71e7f52 ] Use the introduced field for correct operation with VRF devices instead of conditionally overwriting flowic_oif. This is a partial revert of commit b575b24b8eee3 ("netfilter: Fix rpfilter dropping vrf packets by mistake"), implementing a simpler solution. Signed-off-by: Phil Sutter Reviewed-by: David Ahern Reviewed-by: Guillaume Nault Signed-off-by: Florian Westphal Stable-dep-of: 05ef7055debc ("netfilter: fib: check correct rtable in vrf setups") Signed-off-by: Sasha Levin

netfilter: nf_tables: prevent nf_skb_duplicated corruption

2024-10-17T13:08:06+00:00

[ Upstream commit 92ceba94de6fb4cee2bf40b485979c342f44a492 ] syzbot found that nf_dup_ipv4() or nf_dup_ipv6() could write per-cpu variable nf_skb_duplicated in an unsafe way [1]. Disabling preemption as hinted by the splat is not enough, we have to disable soft interrupts as well. [1] BUG: using __this_cpu_write() in preemptible [00000000] code: syz.4.282/6316 caller is nf_dup_ipv4+0x651/0x8f0 net/ipv4/netfilter/nf_dup_ipv4.c:87 CPU: 0 UID: 0 PID: 6316 Comm: syz.4.282 Not tainted 6.11.0-rc7-syzkaller-00104-g7052622fccb1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_preemption_disabled+0x10e/0x120 lib/smp_processor_id.c:49 nf_dup_ipv4+0x651/0x8f0 net/ipv4/netfilter/nf_dup_ipv4.c:87 nft_dup_ipv4_eval+0x1db/0x300 net/ipv4/netfilter/nft_dup_ipv4.c:30 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_ipv4+0x202/0x320 net/netfilter/nft_chain_filter.c:23 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook+0x2c4/0x450 include/linux/netfilter.h:269 NF_HOOK_COND include/linux/netfilter.h:302 [inline] ip_output+0x185/0x230 net/ipv4/ip_output.c:433 ip_local_out net/ipv4/ip_output.c:129 [inline] ip_send_skb+0x74/0x100 net/ipv4/ip_output.c:1495 udp_send_skb+0xacf/0x1650 net/ipv4/udp.c:981 udp_sendmsg+0x1c21/0x2a60 net/ipv4/udp.c:1269 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x1a6/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmmsg+0x3b2/0x740 net/socket.c:2737 __do_sys_sendmmsg net/socket.c:2766 [inline] __se_sys_sendmmsg net/socket.c:2763 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2763 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ce4f7def9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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:00007f4ce5d4a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f4ce5135f80 RCX: 00007f4ce4f7def9 RDX: 0000000000000001 RSI: 0000000020005d40 RDI: 0000000000000006 RBP: 00007f4ce4ff0b76 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4ce5135f80 R15: 00007ffd4cbc6d68 Fixes: d877f07112f1 ("netfilter: nf_tables: add nft_dup expression") Reported-by: syzbot Signed-off-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: tproxy: bail out if IP has been disabled on the device

2024-06-16T11:32:29+00:00

[ Upstream commit 21a673bddc8fd4873c370caf9ae70ffc6d47e8d3 ] syzbot reports: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] [..] RIP: 0010:nf_tproxy_laddr4+0xb7/0x340 net/ipv4/netfilter/nf_tproxy_ipv4.c:62 Call Trace: nft_tproxy_eval_v4 net/netfilter/nft_tproxy.c:56 [inline] nft_tproxy_eval+0xa9a/0x1a00 net/netfilter/nft_tproxy.c:168 __in_dev_get_rcu() can return NULL, so check for this. Reported-and-tested-by: syzbot+b94a6818504ea90d7661@syzkaller.appspotmail.com Fixes: cc6eb4338569 ("tproxy: use the interface primary IP address as a default value for --on-ip") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

netfilter: complete validation of user input

2024-05-02T14:23:34+00:00

[ Upstream commit 65acf6e0501ac8880a4f73980d01b5d27648b956 ] In my recent commit, I missed that do_replace() handlers use copy_from_sockptr() (which I fixed), followed by unsafe copy_from_sockptr_offset() calls. In all functions, we can perform the @optlen validation before even calling xt_alloc_table_info() with the following check: if ((u64)optlen < (u64)tmp.size + sizeof(tmp)) return -EINVAL; Fixes: 0c83842df40f ("netfilter: validate user input for expected length") Reported-by: syzbot Signed-off-by: Eric Dumazet Reviewed-by: Pablo Neira Ayuso Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netfilter: validate user input for expected length

2024-04-13T10:59:25+00:00

commit 0c83842df40f86e529db6842231154772c20edcc upstream. I got multiple syzbot reports showing old bugs exposed by BPF after commit 20f2505fb436 ("bpf: Try to avoid kzalloc in cgroup/{s,g}etsockopt") setsockopt() @optlen argument should be taken into account before copying data. BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline] BUG: KASAN: slab-out-of-bounds in do_replace net/ipv4/netfilter/ip_tables.c:1111 [inline] BUG: KASAN: slab-out-of-bounds in do_ipt_set_ctl+0x902/0x3dd0 net/ipv4/netfilter/ip_tables.c:1627 Read of size 96 at addr ffff88802cd73da0 by task syz-executor.4/7238 CPU: 1 PID: 7238 Comm: syz-executor.4 Not tainted 6.9.0-rc2-next-20240403-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 copy_from_sockptr_offset include/linux/sockptr.h:49 [inline] copy_from_sockptr include/linux/sockptr.h:55 [inline] do_replace net/ipv4/netfilter/ip_tables.c:1111 [inline] do_ipt_set_ctl+0x902/0x3dd0 net/ipv4/netfilter/ip_tables.c:1627 nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101 do_sock_setsockopt+0x3af/0x720 net/socket.c:2311 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x72/0x7a RIP: 0033:0x7fd22067dde9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd21f9ff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fd2207abf80 RCX: 00007fd22067dde9 RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fd2206ca47a R08: 0000000000000001 R09: 0000000000000000 R10: 0000000020000880 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fd2207abf80 R15: 00007ffd2d0170d8 Allocated by task 7238: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:4069 [inline] __kmalloc_noprof+0x200/0x410 mm/slub.c:4082 kmalloc_noprof include/linux/slab.h:664 [inline] __cgroup_bpf_run_filter_setsockopt+0xd47/0x1050 kernel/bpf/cgroup.c:1869 do_sock_setsockopt+0x6b4/0x720 net/socket.c:2293 __sys_setsockopt+0x1ae/0x250 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340 do_syscall_64+0xfb/0x240 entry_SYSCALL_64_after_hwframe+0x72/0x7a The buggy address belongs to the object at ffff88802cd73da0 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of allocated 1-byte region [ffff88802cd73da0, ffff88802cd73da1) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802cd73020 pfn:0x2cd73 flags: 0xfff80000000000(node=0|zone=1|lastcpupid=0xfff) page_type: 0xffffefff(slab) raw: 00fff80000000000 ffff888015041280 dead000000000100 dead000000000122 raw: ffff88802cd73020 000000008080007f 00000001ffffefff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5103, tgid 2119833701 (syz-executor.4), ts 5103, free_ts 70804600828 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1490 prep_new_page mm/page_alloc.c:1498 [inline] get_page_from_freelist+0x2e7e/0x2f40 mm/page_alloc.c:3454 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4712 __alloc_pages_node_noprof include/linux/gfp.h:244 [inline] alloc_pages_node_noprof include/linux/gfp.h:271 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2249 allocate_slab+0x5a/0x2e0 mm/slub.c:2412 new_slab mm/slub.c:2465 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3615 __slab_alloc+0x58/0xa0 mm/slub.c:3705 __slab_alloc_node mm/slub.c:3758 [inline] slab_alloc_node mm/slub.c:3936 [inline] __do_kmalloc_node mm/slub.c:4068 [inline] kmalloc_node_track_caller_noprof+0x286/0x450 mm/slub.c:4089 kstrdup+0x3a/0x80 mm/util.c:62 device_rename+0xb5/0x1b0 drivers/base/core.c:4558 dev_change_name+0x275/0x860 net/core/dev.c:1232 do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2864 __rtnl_newlink net/core/rtnetlink.c:3680 [inline] rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3727 rtnetlink_rcv_msg+0x89b/0x10d0 net/core/rtnetlink.c:6594 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2559 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361 page last free pid 5146 tgid 5146 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1110 [inline] free_unref_page+0xd3c/0xec0 mm/page_alloc.c:2617 discard_slab mm/slub.c:2511 [inline] __put_partials+0xeb/0x130 mm/slub.c:2980 put_cpu_partial+0x17c/0x250 mm/slub.c:3055 __slab_free+0x2ea/0x3d0 mm/slub.c:4254 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3888 [inline] slab_alloc_node mm/slub.c:3948 [inline] __do_kmalloc_node mm/slub.c:4068 [inline] __kmalloc_node_noprof+0x1d7/0x450 mm/slub.c:4076 kmalloc_node_noprof include/linux/slab.h:681 [inline] kvmalloc_node_noprof+0x72/0x190 mm/util.c:634 bucket_table_alloc lib/rhashtable.c:186 [inline] rhashtable_rehash_alloc+0x9e/0x290 lib/rhashtable.c:367 rht_deferred_worker+0x4e1/0x2440 lib/rhashtable.c:427 process_one_work kernel/workqueue.c:3218 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299 worker_thread+0x86d/0xd70 kernel/workqueue.c:3380 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 Memory state around the buggy address: ffff88802cd73c80: 07 fc fc fc 05 fc fc fc 05 fc fc fc fa fc fc fc ffff88802cd73d00: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc >ffff88802cd73d80: fa fc fc fc 01 fc fc fc fa fc fc fc fa fc fc fc ^ ffff88802cd73e00: fa fc fc fc fa fc fc fc 05 fc fc fc 07 fc fc fc ffff88802cd73e80: 07 fc fc fc 07 fc fc fc 07 fc fc fc 07 fc fc fc Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot Signed-off-by: Eric Dumazet Reviewed-by: Pablo Neira Ayuso Link: https://lore.kernel.org/r/20240404122051.2303764-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: add and use nft_sk helper

2023-10-10T19:53:29+00:00

[ Upstream commit 85554eb981e5a8b0b8947611193aef1737081ef2 ] This allows to change storage placement later on without changing readers. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Stable-dep-of: 28427f368f0e ("netfilter: nft_exthdr: Fix non-linear header modification") Signed-off-by: Sasha Levin