Description
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.
References6
- git.kernel.org/stable/c/094f0a895cf97a993d06d5dc4c12e7cb7da845a5
- git.kernel.org/stable/c/1757598b3804f7cb35b5b5e02558f6d8b9c2f254
- git.kernel.org/stable/c/48a0209d8da0d90a7b0a0db19d1ff88027b13781
- git.kernel.org/stable/c/61aaa8782bec59ecffd22e030f54ef9351bcabf9
- git.kernel.org/stable/c/a5c6316052f0ff1467221ecf2996cbab0a496b1e
- git.kernel.org/stable/c/d02035c5eb4955616efc5c6dbe3d98f19d798cb2
Metrics
- CVSS 3.1
-
7.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 6 · as of 8 November 2026
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