High 7.8Published Aug 10, 2026

CVE-2026-68284bpf, sockmap: Fix cork use-after-free in tcp_bpf_sendmsg()

Updated under an hour ago (Oct 28, 2026, 5:40 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix cork use-after-free in tcp_bpf_sendmsg() tcp_bpf_sendmsg() keeps msg_tx across sk_stream_wait_memory(), which drops and reacquires the socket lock. Its error path tries to decide whether msg_tx names the local temporary message by comparing it with the current value of psock->cork. This comparison is unsafe when two threads send on the same socket: Thread A Thread B msg_tx = psock->cork sk_msg_alloc() fails sk_stream_wait_memory() releases the socket lock acquires the socket lock completes the cork psock->cork = NULL frees the cork reacquires the socket lock msg_tx != psock->cork sk_msg_free(msg_tx) The stale cork is therefore mistaken for the local temporary message and freed again. KASAN reported: BUG: KASAN: slab-use-after-free in sk_msg_free+0x49/0x50 Read of size 4 at addr ffff88810c908800 by task poc/90 Call Trace: sk_msg_free+0x49/0x50 tcp_bpf_sendmsg+0x14f5/0x1cc0 __sys_sendto+0x32c/0x3a0 __x64_sys_sendto+0xdb/0x1b0 Allocated by task 89: __kasan_kmalloc+0x8f/0xa0 tcp_bpf_sendmsg+0x16b3/0x1cc0 Freed by task 91: __kasan_slab_free+0x43/0x70 kfree+0x131/0x3c0 tcp_bpf_sendmsg+0xec3/0x1cc0 msg_tx can only name the stack-local tmp or the shared cork. Check for tmp directly so a changed psock->cork cannot turn a shared message into an apparent local one.

CVSS: 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-416
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Received
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	604326b41a6fb9b4a78b6179335decee0365cd8c builds before 0688e6fe599d2d39147ae9ece97944c6e1815ebf; from 604326b41a6fb9b4a78b6179335decee0365cd8c before b2bcbeabfd843d47468fa095b1bd08ddb90cf616; 604326b41a6fb9b4a78b6179335decee0365cd8c builds before 54be47e7cbb936429c3bbdfc526ea943954aaf80; from 604326b41a6fb9b4a78b6179335decee0365cd8c before ee762f684eefa59de34d9ed93cab08336e834f47; from 604326b41a6fb9b4a78b6179335decee0365cd8c before cde4d6bcd9b73073c66498f6723c7b364c4dbc18; 604326b41a6fb9b4a78b6179335decee0365cd8c builds before 786d690257ec7a0c839f8710456e444ce3f1348b; 604326b41a6fb9b4a78b6179335decee0365cd8c builds before 752b1159ed5d0c48fe169a3721b96660a9822aa1; 604326b41a6fb9b4a78b6179335decee0365cd8c builds before 2d66a033864e27ab8d5e44cb36f31d9d2413bee4	CNA record

References

References

https://git.kernel.org/stable/c/0688e6fe599d2d39147ae9ece97944c6e1815ebf
https://git.kernel.org/stable/c/b2bcbeabfd843d47468fa095b1bd08ddb90cf616
https://git.kernel.org/stable/c/54be47e7cbb936429c3bbdfc526ea943954aaf80
https://git.kernel.org/stable/c/ee762f684eefa59de34d9ed93cab08336e834f47
https://git.kernel.org/stable/c/cde4d6bcd9b73073c66498f6723c7b364c4dbc18
https://git.kernel.org/stable/c/786d690257ec7a0c839f8710456e444ce3f1348b
https://git.kernel.org/stable/c/752b1159ed5d0c48fe169a3721b96660a9822aa1
https://git.kernel.org/stable/c/2d66a033864e27ab8d5e44cb36f31d9d2413bee4

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.