kernel/linux.git/net/ipv4/af_inet.c, branch v6.18.22

net: gro: remove unnecessary df checks

2025-09-25T10:42:49+00:00

Currently, packets with fixed IDs will be merged only if their don't-fragment bit is set. This restriction is unnecessary since packets without the don't-fragment bit will be forwarded as-is even if they were merged together. The merged packets will be segmented into their original forms before being forwarded, either by GSO or by TSO. The IDs will also remain identical unless NETIF_F_TSO_MANGLEID is set, in which case the IDs can become incrementing, which is also fine. Clean up the code by removing the unnecessary don't-fragment checks. Signed-off-by: Richard Gobert Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250923085908.4687-5-richardbgobert@gmail.com Signed-off-by: Paolo Abeni

net: gso: restore ids of outer ip headers correctly

2025-09-25T10:42:49+00:00

Currently, NETIF_F_TSO_MANGLEID indicates that the inner-most ID can be mangled. Outer IDs can always be mangled. Make GSO preserve outer IDs by default, with NETIF_F_TSO_MANGLEID allowing both inner and outer IDs to be mangled. This commit also modifies a few drivers that use SKB_GSO_FIXEDID directly. Signed-off-by: Richard Gobert Reviewed-by: Edward Cree # for sfc Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20250923085908.4687-4-richardbgobert@gmail.com Signed-off-by: Paolo Abeni

net: modify core data structures for PSP datapath support

2025-09-18T10:32:06+00:00

Add pointers to psp data structures to core networking structs, and an SKB extension to carry the PSP information from the drivers to the socket layer. Reviewed-by: Willem de Bruijn Signed-off-by: Jakub Kicinski Co-developed-by: Daniel Zahka Signed-off-by: Daniel Zahka Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250917000954.859376-4-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni

net: Retire DCCP socket.

2025-04-12T01:58:10+00:00

DCCP was orphaned in 2021 by commit 054c4610bd05 ("MAINTAINERS: dccp: move Gerrit Renker to CREDITS"), which noted that the last maintainer had been inactive for five years. In recent years, it has become a playground for syzbot, and most changes to DCCP have been odd bug fixes triggered by syzbot. Apart from that, the only changes have been driven by treewide or networking API updates or adjustments related to TCP. Thus, in 2023, we announced we would remove DCCP in 2025 via commit b144fcaf46d4 ("dccp: Print deprecation notice."). Since then, only one individual has contacted the netdev mailing list. [0] There is ongoing research for Multipath DCCP. The repository is hosted on GitHub [1], and development is not taking place through the upstream community. While the repository is published under the GPLv2 license, the scheduling part remains proprietary, with a LICENSE file [2] stating: "This is not Open Source software." The researcher mentioned a plan to address the licensing issue, upstream the patches, and step up as a maintainer, but there has been no further communication since then. Maintaining DCCP for a decade without any real users has become a burden. Therefore, it's time to remove it. Removing DCCP will also provide significant benefits to TCP. It allows us to freely reorganize the layout of struct inet_connection_sock, which is currently shared with DCCP, and optimize it to reduce the number of cachelines accessed in the TCP fast path. Note that we keep DCCP netfilter modules as requested. [3] Link: https://lore.kernel.org/netdev/20230710182253.81446-1-kuniyu@amazon.com/T/#u #[0] Link: https://github.com/telekom/mp-dccp #[1] Link: https://github.com/telekom/mp-dccp/blob/mpdccp_v03_k5.10/net/dccp/non_gpl_scheduler/LICENSE #[2] Link: https://lore.kernel.org/netdev/Z_VQ0KlCRkqYWXa-@calendula/ #[3] Signed-off-by: Kuniyuki Iwashima Acked-by: Paul Moore (LSM and SELinux) Acked-by: Casey Schaufler Link: https://patch.msgid.link/20250410023921.11307-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

net: dismiss sk_forward_alloc_get()

2025-02-20T03:05:28+00:00

After the previous patch we can remove the forward_alloc_get proto callback, basically reverting commit 292e6077b040 ("net: introduce sk_forward_alloc_get()") and commit 66d58f046c9d ("net: use sk_forward_alloc_get() in sk_get_meminfo()"). Signed-off-by: Paolo Abeni Acked-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250218-net-next-mptcp-rx-path-refactor-v1-5-4a47d90d7998@kernel.org Signed-off-by: Jakub Kicinski

ipv4: Define inet_sk_init_flowi4() and use it in inet_sk_rebuild_header().

2024-12-20T21:50:09+00:00

IPv4 code commonly has to initialise a flowi4 structure from an IPv4 socket. This requires looking at potential IPv4 options to set the proper destination address, call flowi4_init_output() with the correct set of parameters and run the sk_classify_flow security hook. Instead of reimplementing these operations in different parts of the stack, let's define inet_sk_init_flowi4() which does all these operations. The first user is inet_sk_rebuild_header(), where inet_sk_init_flowi4() replaces ip_route_output_ports(). Unlike ip_route_output_ports(), which sets the flowi4 structure and performs the route lookup in one go, inet_sk_init_flowi4() only initialises the flow. The route lookup is then done by ip_route_output_flow(). Decoupling flow initialisation from route lookup makes this new interface applicable more broadly as it will allow some users to overwrite specific struct flowi4 members before the route lookup. Signed-off-by: Guillaume Nault Link: https://patch.msgid.link/fd416275262b1f518d5abfcef740ce4f4a1a6522.1734357769.git.gnault@redhat.com Signed-off-by: Jakub Kicinski

net: inet: do not leave a dangling sk pointer in inet_create()

2024-10-16T01:43:08+00:00

sock_init_data() attaches the allocated sk object to the provided sock object. If inet_create() fails later, the sk object is freed, but the sock object retains the dangling pointer, which may create use-after-free later. Clear the sk pointer in the sock object on error. Signed-off-by: Ignat Korchagin Reviewed-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20241014153808.51894-7-ignat@cloudflare.com Signed-off-by: Jakub Kicinski

net: gro: initialize network_offset in network layer

2024-05-27T23:46:59+00:00

Syzkaller was able to trigger kernel BUG at net/core/gro.c:424 ! RIP: 0010:gro_pull_from_frag0 net/core/gro.c:424 [inline] RIP: 0010:gro_try_pull_from_frag0 net/core/gro.c:446 [inline] RIP: 0010:dev_gro_receive+0x242f/0x24b0 net/core/gro.c:571 Due to using an incorrect NAPI_GRO_CB(skb)->network_offset. The referenced commit sets this offset to 0 in skb_gro_reset_offset. That matches the expected case in dev_gro_receive: pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive, ipv6_gro_receive, inet_gro_receive, &gro_list->list, skb); But syzkaller injected an skb with protocol ETH_P_TEB into an ip6gre device (by writing the IP6GRE encapsulated version to a TAP device). The result was a first call to eth_gro_receive, and thus an extra ETH_HLEN in network_offset that should not be there. First issue hit is when computing offset from network header in ipv6_gro_pull_exthdrs. Initialize both offsets in the network layer gro_receive. This pairs with all reads in gro_receive, which use skb_gro_receive_network_offset(). Fixes: 186b1ea73ad8 ("net: gro: use cb instead of skb->network_header") Reported-by: syzkaller Signed-off-by: Willem de Bruijn CC: Richard Gobert Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20240523141434.1752483-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski

Merge tag 'net-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-05-23T19:49:37+00:00

Pull networking fixes from Paolo Abeni: "Quite smaller than usual. Notably it includes the fix for the unix regression from the past weeks. The TCP window fix will require some follow-up, already queued. Current release - regressions: - af_unix: fix garbage collection of embryos Previous releases - regressions: - af_unix: fix race between GC and receive path - ipv6: sr: fix missing sk_buff release in seg6_input_core - tcp: remove 64 KByte limit for initial tp->rcv_wnd value - eth: r8169: fix rx hangup - eth: lan966x: remove ptp traps in case the ptp is not enabled - eth: ixgbe: fix link breakage vs cisco switches - eth: ice: prevent ethtool from corrupting the channels Previous releases - always broken: - openvswitch: set the skbuff pkt_type for proper pmtud support - tcp: Fix shift-out-of-bounds in dctcp_update_alpha() Misc: - a bunch of selftests stabilization patches" * tag 'net-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (25 commits) r8169: Fix possible ring buffer corruption on fragmented Tx packets. idpf: Interpret .set_channels() input differently ice: Interpret .set_channels() input differently nfc: nci: Fix handling of zero-length payload packets in nci_rx_work() net: relax socket state check at accept time. tcp: remove 64 KByte limit for initial tp->rcv_wnd value net: ti: icssg_prueth: Fix NULL pointer dereference in prueth_probe() tls: fix missing memory barrier in tls_init net: fec: avoid lock evasion when reading pps_enable Revert "ixgbe: Manual AN-37 for troublesome link partners for X550 SFI" testing: net-drv: use stats64 for testing net: mana: Fix the extra HZ in mana_hwc_send_request net: lan966x: Remove ptp traps in case the ptp is not enabled. openvswitch: Set the skbuff pkt_type for proper pmtud support. selftest: af_unix: Make SCM_RIGHTS into OOB data. af_unix: Fix garbage collection of embryos carrying OOB with SCM_RIGHTS tcp: Fix shift-out-of-bounds in dctcp_update_alpha(). selftests/net: use tc rule to filter the na packet ipv6: sr: fix memleak in seg6_hmac_init_algo af_unix: Update unix_sk(sk)->oob_skb under sk_receive_queue lock. ...

net: relax socket state check at accept time.

2024-05-23T10:33:35+00:00

Christoph reported the following splat: WARNING: CPU: 1 PID: 772 at net/ipv4/af_inet.c:761 __inet_accept+0x1f4/0x4a0 Modules linked in: CPU: 1 PID: 772 Comm: syz-executor510 Not tainted 6.9.0-rc7-g7da7119fe22b #56 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 RIP: 0010:__inet_accept+0x1f4/0x4a0 net/ipv4/af_inet.c:759 Code: 04 38 84 c0 0f 85 87 00 00 00 41 c7 04 24 03 00 00 00 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 ec b7 da fd <0f> 0b e9 7f fe ff ff e8 e0 b7 da fd 0f 0b e9 fe fe ff ff 89 d9 80 RSP: 0018:ffffc90000c2fc58 EFLAGS: 00010293 RAX: ffffffff836bdd14 RBX: 0000000000000000 RCX: ffff888104668000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff836bdb89 R09: fffff52000185f64 R10: dffffc0000000000 R11: fffff52000185f64 R12: dffffc0000000000 R13: 1ffff92000185f98 R14: ffff88810754d880 R15: ffff8881007b7800 FS: 000000001c772880(0000) GS:ffff88811b280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb9fcf2e178 CR3: 00000001045d2002 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: inet_accept+0x138/0x1d0 net/ipv4/af_inet.c:786 do_accept+0x435/0x620 net/socket.c:1929 __sys_accept4_file net/socket.c:1969 [inline] __sys_accept4+0x9b/0x110 net/socket.c:1999 __do_sys_accept net/socket.c:2016 [inline] __se_sys_accept net/socket.c:2013 [inline] __x64_sys_accept+0x7d/0x90 net/socket.c:2013 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0x100 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x4315f9 Code: fd ff 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 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 0f 83 ab b4 fd ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffdb26d9c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002b RAX: ffffffffffffffda RBX: 0000000000400300 RCX: 00000000004315f9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00000000006e1018 R08: 0000000000400300 R09: 0000000000400300 R10: 0000000000400300 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000040cdf0 R14: 000000000040ce80 R15: 0000000000000055 The reproducer invokes shutdown() before entering the listener status. After commit 94062790aedb ("tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets"), the above causes the child to reach the accept syscall in FIN_WAIT1 status. Eric noted we can relax the existing assertion in __inet_accept() Reported-by: Christoph Paasch Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/490 Suggested-by: Eric Dumazet Fixes: 94062790aedb ("tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets") Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/23ab880a44d8cfd967e84de8b93dbf48848e3d8c.1716299669.git.pabeni@redhat.com Signed-off-by: Paolo Abeni