CVE-2026-92485 PUBLISHED

bpf: Fix WARNING in bpf_tracing_link_release

Assigner: Linux
Reserved: 16.09.2026 Published: 17.09.2026 Updated: 17.09.2026

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

bpf: Fix WARNING in bpf_tracing_link_release

The trampoline could be corrupted by the blindly 'tr->flags = BPF_TRAMP_F_TAIL_CALL_CTX' in verifier.

  1. A fexit attached to a tail_call_reachable prog. 'tr->flags' became 'BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_TAIL_CALL_CTX'. And, the trampoline would poke the target prog's nop insn using jmp insn instead of call insn.
  2. Another fexit loaded with the same tail_call_reachable prog target. 'tr->flags' became 'BPF_TRAMP_F_TAIL_CALL_CTX'.
  3. Close the first fexit link. Due to no BPF_TRAMP_F_CALL_ORIG in 'tr->flags', the trampoline will fail to restore the prog's nop insn using call insn.

[ 3.410719] WARNING: kernel/bpf/syscall.c:3551 at bpf_tracing_link_release+0x53/0x60, CPU#1: test_progs/98 ... [ 3.428793] bpf_link_free+0x58/0x130 [ 3.429293] bpf_link_release+0x23/0x30

Fix the warning by updating 'tr->flags' with '|=' and lock.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 2b5dcb31a19a2e0acd869b12c9db9b2d696ef544 to 48a0209d8da0d90a7b0a0db19d1ff88027b13781 (excl.)
  • affected from 2b5dcb31a19a2e0acd869b12c9db9b2d696ef544 to 61aaa8782bec59ecffd22e030f54ef9351bcabf9 (excl.)
  • Version 605c8d8f9966fcd2f0b858fabebe416fc83f2209 is affected
  • Version 028480eaf2a1401e914a1fa1a4a21d877cf0ae30 is affected
  • Version 8f873cc3f67f2257493063e57d0caf07ef889ee9 is affected
  • affected from 6.1.72 to 6.2 (excl.)
  • affected from 6.5.12 to 6.6 (excl.)
  • affected from 6.6.2 to 6.7 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.7 is affected
  • unaffected from 0 to 6.7 (excl.)
  • unaffected from 7.2.6 to 7.2.* (incl.)
  • unaffected from 7.3-rc1 to * (incl.)

References