CVE-2026-98039

NameCVE-2026-98039
DescriptionIn the Linux kernel, the following vulnerability has been resolved: bpf: Require MEM_PERCPU for percpu kptr stores map_kptr_match_type() treats perm_flags as the set of register type flags that a kptr field permits. Adding MEM_PERCPU to that set for BPF_KPTR_PERCPU does not require the source register to carry it, however. The subset test consequently accepts both a plain bpf_obj_new() allocation and a referenced kernel pointer into a __percpu_kptr map field. Loads from the field are always marked MEM_PERCPU. Consumers then treat the stored value as the cookie returned by bpf_percpu_obj_new(): per-CPU pointer helpers relocate it, and map teardown selects the per-CPU free path. A plain allocation can therefore provide an arbitrary kernel read/write, while a kernel pointer can be relocated into an invalid address or sent through a missing destructor. Require the source MEM_PERCPU flag to match the destination field kind. This preserves valid bpf_percpu_obj_new() stores and rejects both the program-BTF and kernel-BTF variants.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-4817-1, DSA-6528-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
linux (PTS)bookworm6.1.176-1fixed
bookworm (security)6.1.190-1fixed
trixie6.12.107-1vulnerable
trixie (security)6.12.113-1fixed
forky7.2.9-1fixed
sid7.2.11-1fixed
linux-6.12 (PTS)bookworm (security)6.12.111-1~deb12u1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
linuxsourcebookworm(not affected)
linuxsourcetrixie6.12.111-1DSA-6528-1
linuxsource(unstable)7.2.7-1
linux-6.12sourcebookworm6.12.111-1~deb12u1DLA-4817-1

Notes

[bookworm] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/048029ba1c793f8cabc4ad5eea765da01903f8f1 (7.3-rc2)

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