CVE-2026-31526

MEDIUM EPSS 1.1%
Published Apr 22, 20262mo ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
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Published Apr 22, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix exception exit lock checking for subprogs process_bpf_exit_full() passes check_lock = !curframe to check_resource_leak(), which is false in cases when bpf_throw() is called from a static subprog. This makes check_resource_leak() to skip validation of active_rcu_locks, active_preempt_locks, and active_irq_id on exception exits from subprogs. At runtime bpf_throw() unwinds the stack via ORC without releasing any user-acquired locks, which may cause various issues as the result. Fix by setting check_lock = true for exception exits regardless of curframe, since exceptions bypass all intermediate frame cleanup. Update the error message prefix to "bpf_throw" for exception exits to distinguish them from normal BPF_EXIT. Fix reject_subprog_with_rcu_read_lock test which was previously passing for the wrong reason. Test program returned directly from the subprog call without closing the RCU section, so the error was triggered by the unclosed RCU lock on normal exit, not by bpf_throw. Update __msg annotations for affected tests to match the new "bpf_throw" error prefix. The spin_lock case is not affected because they are already checked [1] at the call site in do_check_insn() before bpf_throw can run. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/kernel/bpf/verifier.c?h=v7.0-rc4#n21098

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
1.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-667

Affected Products 6

VendorProductVersionRange
linuxlinux_kernel*≥6.7  –  <6.18.21
linuxlinux_kernel*≥6.19  –  <6.19.11
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any

References 3

  • git.kernel.org https://git.kernel.org/stable/c/5a399f3117642494e35545f6ca397d3e177c1f9b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6c2128505f61b504c79a20b89596feba61388112
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c0281da1f2aa5c2fca3a05f79b86bea96591c358
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/5a399f3117642494e35545f6ca397d3e177c1f9b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6c2128505f61b504c79a20b89596feba61388112
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c0281da1f2aa5c2fca3a05f79b86bea96591c358
    Patch