CVE-2026-98062: bpf: Mark signal tracepoint siginfo arguments as scalar

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-25 · updated 2026-10-21
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Mark signal tracepoint siginfo arguments as scalar The signal_generate and signal_deliver tracepoints declare their info argument as a struct kernel_siginfo pointer. btf_ctx_access() therefore treats it as a trusted pointer for tp_btf programs. Signal delivery also uses SEND_SIG_NOINFO and SEND_SIG_PRIV as special values for this argument. Those values are zero and one respectively, and are not pointers. A tp_btf program can currently dereference either value and fault the kernel. In particular, signal_generate can run from timer interrupt context, turning the fault into a kernel panic. Record both tracepoints in raw_tp_null_args[] and mark argument one as a non-pointer. This preserves scalar access to the cookie while rejecting direct and helper-mediated pointer use. Merely marking it nullable would not suffice because SEND_SIG_PRIV is nonzero.

Affected products

Linux kernel: from 6.12.6 before 6.13; from 6.13.1 before 6.18.53; from 6.19 before 7.2.7; 6.13, 6.13-rc3, 6.13-rc4, 6.13-rc5, 6.13-rc6, 6.13-rc7 (+1) — fixed in 6.13, 6.18.53, 7.2.7

How to fix

Upgrade to a fixed version: Linux kernel 6.13, 6.18.53, 7.2.7. Check the vendor advisory for mitigations.

References

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