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Description

In the Linux kernel, the following vulnerability has been resolved: net: fix data-races around sk->sk_forward_alloc Syzkaller reported this warning: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 16 at net/ipv4/af_inet.c:156 inet_sock_destruct+0x1c5/0x1e0 Modules linked in: CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc5 #26 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:inet_sock_destruct+0x1c5/0x1e0 Code: 24 12 4c 89 e2 5b 48 c7 c7 98 ec bb 82 41 5c e9 d1 18 17 ff 4c 89 e6 5b 48 c7 c7 d0 ec bb 82 41 5c e9 bf 18 17 ff 0f 0b eb 83 <0f> 0b eb 97 0f 0b eb 87 0f 0b e9 68 ff ff ff 66 66 2e 0f 1f 84 00 RSP: 0018:ffffc9000008bd90 EFLAGS: 00010206 RAX: 0000000000000300 RBX: ffff88810b172a90 RCX: 0000000000000007 RDX: 0000000000000002 RSI: 0000000000000300 RDI: ffff88810b172a00 RBP: ffff88810b172a00 R08: ffff888104273c00 R09: 0000000000100007 R10: 0000000000020000 R11: 0000000000000006 R12: ffff88810b172a00 R13: 0000000000000004 R14: 0000000000000000 R15: ffff888237c31f78 FS: 0000000000000000(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc63fecac8 CR3: 000000000342e000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? __warn+0x88/0x130 ? inet_sock_destruct+0x1c5/0x1e0 ? report_bug+0x18e/0x1a0 ? handle_bug+0x53/0x90 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? inet_sock_destruct+0x1c5/0x1e0 __sk_destruct+0x2a/0x200 rcu_do_batch+0x1aa/0x530 ? rcu_do_batch+0x13b/0x530 rcu_core+0x159/0x2f0 handle_softirqs+0xd3/0x2b0 ? __pfx_smpboot_thread_fn+0x10/0x10 run_ksoftirqd+0x25/0x30 smpboot_thread_fn+0xdd/0x1d0 kthread+0xd3/0x100 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x34/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> ---[ end trace 0000000000000000 ]--- Its possible that two threads call tcp_v6_do_rcv()/sk_forward_alloc_add() concurrently when sk->sk_state == TCP_LISTEN with sk->sk_lock unlocked, which triggers a data-race around sk->sk_forward_alloc: tcp_v6_rcv tcp_v6_do_rcv skb_clone_and_charge_r sk_rmem_schedule __sk_mem_schedule sk_forward_alloc_add() skb_set_owner_r sk_mem_charge sk_forward_alloc_add() __kfree_skb skb_release_all skb_release_head_state sock_rfree sk_mem_uncharge sk_forward_alloc_add() sk_mem_reclaim // set local var reclaimable __sk_mem_reclaim sk_forward_alloc_add() In this syzkaller testcase, two threads call tcp_v6_do_rcv() with skb->truesize=768, the sk_forward_alloc changes like this: (cpu 1) | (cpu 2) | sk_forward_alloc ... | ... | 0 __sk_mem_schedule() | | +4096 = 4096 | __sk_mem_schedule() | +4096 = 8192 sk_mem_charge() | | -768 = 7424 | sk_mem_charge() | -768 = 6656 ... | ... | sk_mem_uncharge() | | +768 = 7424 reclaimable=7424 | | | sk_mem_uncharge() | +768 = 8192 | reclaimable=8192 | __sk_mem_reclaim() | | -4096 = 4096 | __sk_mem_reclaim() | -8192 = -4096 != 0 The skb_clone_and_charge_r() should not be called in tcp_v6_do_rcv() when sk->sk_state is TCP_LISTEN, it happens later in tcp_v6_syn_recv_sock(). Fix the same issue in dccp_v6_do_rcv().

PUBLISHED Reserved 2024-11-19 | Published 2024-12-02 | Updated 2025-11-03 | Assigner Linux

Product status

Default status
unaffected

e994b2f0fb9229aeff5eea9541320bd7b2ca8714 (git) before 695fb0b9aecfd5dd5b2946ba8897ac2c1eef654d
affected

e994b2f0fb9229aeff5eea9541320bd7b2ca8714 (git) before fe2c0bd6d1e29ccefdc978b9a290571c93c27473
affected

e994b2f0fb9229aeff5eea9541320bd7b2ca8714 (git) before c3d052cae566ec2285f5999958a5deb415a0f59e
affected

e994b2f0fb9229aeff5eea9541320bd7b2ca8714 (git) before be7c61ea5f816168c38955eb4e898adc8b4b32fd
affected

e994b2f0fb9229aeff5eea9541320bd7b2ca8714 (git) before 3f51f8c9d28954cf380100883a02eed35a8277e9
affected

e994b2f0fb9229aeff5eea9541320bd7b2ca8714 (git) before d285eb9d0641c8344f2836081b4ccb7b3c5cc1b6
affected

e994b2f0fb9229aeff5eea9541320bd7b2ca8714 (git) before 073d89808c065ac4c672c0a613a71b27a80691cb
affected

Default status
affected

4.4
affected

Any version before 4.4
unaffected

5.4.290 (semver)
unaffected

5.10.234 (semver)
unaffected

5.15.177 (semver)
unaffected

6.1.127 (semver)
unaffected

6.6.74 (semver)
unaffected

6.11.10 (semver)
unaffected

6.12 (original_commit_for_fix)
unaffected

References

lists.debian.org/debian-lts-announce/2025/03/msg00001.html

lists.debian.org/debian-lts-announce/2025/03/msg00002.html

git.kernel.org/...c/695fb0b9aecfd5dd5b2946ba8897ac2c1eef654d

git.kernel.org/...c/fe2c0bd6d1e29ccefdc978b9a290571c93c27473

git.kernel.org/...c/c3d052cae566ec2285f5999958a5deb415a0f59e

git.kernel.org/...c/be7c61ea5f816168c38955eb4e898adc8b4b32fd

git.kernel.org/...c/3f51f8c9d28954cf380100883a02eed35a8277e9

git.kernel.org/...c/d285eb9d0641c8344f2836081b4ccb7b3c5cc1b6

git.kernel.org/...c/073d89808c065ac4c672c0a613a71b27a80691cb

cve.org (CVE-2024-53124)

nvd.nist.gov (CVE-2024-53124)

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