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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2026-68284

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

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Status
Published
Published
Updated
Assigning organization
Linux

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 604326b41a6fb9b4a78b6179335decee0365cd8c to < 0688e6fe599d2d39147ae9ece97944c6e1815ebfaffected
  • 604326b41a6fb9b4a78b6179335decee0365cd8c to < b2bcbeabfd843d47468fa095b1bd08ddb90cf616affected
  • 604326b41a6fb9b4a78b6179335decee0365cd8c to < 54be47e7cbb936429c3bbdfc526ea943954aaf80affected
  • 604326b41a6fb9b4a78b6179335decee0365cd8c to < ee762f684eefa59de34d9ed93cab08336e834f47affected
  • 604326b41a6fb9b4a78b6179335decee0365cd8c to < cde4d6bcd9b73073c66498f6723c7b364c4dbc18affected
  • 604326b41a6fb9b4a78b6179335decee0365cd8c to < 786d690257ec7a0c839f8710456e444ce3f1348baffected
  • 604326b41a6fb9b4a78b6179335decee0365cd8c to < 752b1159ed5d0c48fe169a3721b96660a9822aa1affected
  • 604326b41a6fb9b4a78b6179335decee0365cd8c to < 2d66a033864e27ab8d5e44cb36f31d9d2413bee4affected

Linux Linux

Default version status: affected

  • 4.20affected
  • 0 to < 4.20unaffected
  • 5.10.265 to ≤ 5.10.*unaffected
  • 5.15.216 to ≤ 5.15.*unaffected
  • 6.1.183 to ≤ 6.1.*unaffected
  • 6.6.148 to ≤ 6.6.*unaffected
  • 6.12.101 to ≤ 6.12.*unaffected
  • 6.18.42 to ≤ 6.18.*unaffected
  • 7.1.6 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References