CVE-2026-99213

vsock: treat TCP_CLOSING as once-established

State: Published
Severity: Not scored
Published: Oct 28, 2026
Updated: Oct 30, 2026
Reserved: Sep 25, 2026

Description

In the Linux kernel, the following vulnerability has been resolved:

vsock: treat TCP_CLOSING as once-established

Handle the TCP_ESTABLISHED -> TCP_CLOSING transition on OP_RST, which can race with the connect loop. Immediately break and return 0 on ESTABLISHED/CLOSING. The return value of connect() should reflect what happened up to the point the connection was established or failed. Events that occur afterwards must not affect it. E.g. even if OP_RW has already set sk_err, connect() should still return 0, not ENOBUFS because of it. Adapt the inaccurate comment above signal_pending().

Resetting a socket that is still present in connected_table can lead to memory corruption. The reporter noted lost transports for in-flight skbs, and I have reproduced crashes caused by re-insertion into connected_table.

list_add double add: new=, prev=, next=. kernel BUG at lib/list_debug.c:35! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI Workqueue: vsock-loopback vsock_loopback_work RIP: 0010:__list_add_valid_or_report+0x11f/0x130 Call Trace: vsock_insert_connected.cold+0xe/0x13 virtio_transport_recv_pkt+0x10e9/0x1460 vsock_loopback_work+0x305/0x480 process_one_work+0xe4c/0x1560 worker_thread+0x4f1/0xd60 kthread+0x36e/0x470 ret_from_fork+0x47b/0x6b0 ret_from_fork_asm+0x1a/0x30

This fix is supplementary to commit 002541ef650b ("vsock: Ignore signal/timeout on connect() if already established"). Details under Link.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	d021c344051af91f42c5ba9fdedc176740cbd238 to before ea36ef3c229d54b552432d1290aee1d807f67fd5Affected d021c344051af91f42c5ba9fdedc176740cbd238 to before 5f2ab77028602a22f0cc33cac063a313787cbeaeAffected d021c344051af91f42c5ba9fdedc176740cbd238 to before f89770c7365748d9d6a2ae07d1c23497ca21ec07Affected d021c344051af91f42c5ba9fdedc176740cbd238 to before deb972c7eea8d0bc3109c35c30a1c86d4939f811Affected d021c344051af91f42c5ba9fdedc176740cbd238 to before baf1b5715640e434249ce7f63f94bd1a00938ef9Affected d021c344051af91f42c5ba9fdedc176740cbd238 to before c2c5359ef2c33684fa3f3652fd761a483db8d1e7Affected d021c344051af91f42c5ba9fdedc176740cbd238 to before 44d1ca05d6094a5d75c671a0545249186d790b8dAffected d021c344051af91f42c5ba9fdedc176740cbd238 to before 4f6ac74fa594a918d41255c941256e1d51592d3bAffected
LinuxLinux	3.9Affected before 3.9Not affected 5.10.273 through 5.10.Not affected 5.15.224 through 5.15.Not affected 6.1.191 through 6.1.Not affected 6.6.161 through 6.6.Not affected 6.12.115 through 6.12.Not affected 6.18.59 through 6.18.Not affected 7.2.13 through 7.2.*Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

d021c344051af91f42c5ba9fdedc176740cbd238 to before ea36ef3c229d54b552432d1290aee1d807f67fd5Affected
d021c344051af91f42c5ba9fdedc176740cbd238 to before 5f2ab77028602a22f0cc33cac063a313787cbeaeAffected
d021c344051af91f42c5ba9fdedc176740cbd238 to before f89770c7365748d9d6a2ae07d1c23497ca21ec07Affected
d021c344051af91f42c5ba9fdedc176740cbd238 to before deb972c7eea8d0bc3109c35c30a1c86d4939f811Affected
d021c344051af91f42c5ba9fdedc176740cbd238 to before baf1b5715640e434249ce7f63f94bd1a00938ef9Affected
d021c344051af91f42c5ba9fdedc176740cbd238 to before c2c5359ef2c33684fa3f3652fd761a483db8d1e7Affected
d021c344051af91f42c5ba9fdedc176740cbd238 to before 44d1ca05d6094a5d75c671a0545249186d790b8dAffected
d021c344051af91f42c5ba9fdedc176740cbd238 to before 4f6ac74fa594a918d41255c941256e1d51592d3bAffected

LinuxLinux

3.9Affected
before 3.9Not affected
5.10.273 through 5.10.*Not affected
5.15.224 through 5.15.*Not affected
6.1.191 through 6.1.*Not affected
6.6.161 through 6.6.*Not affected
6.12.115 through 6.12.*Not affected
6.18.59 through 6.18.*Not affected
7.2.13 through 7.2.*Not affected
7.3 and laterNot affected

References

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