Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix vmlinux BTF prep race in bpf_get_btf_vmlinux bpf_get_btf_vmlinux() lazily parses the vmlinux BTF under the bpf_verifier_lock, but publishes the result through a plain store and re-checks it through a plain lockless load. Nothing orders the stores initializing the struct btf inside btf_parse_vmlinux() against the store publishing the pointer: On a weakly ordered arch, a concurrent first-time caller taking the lockless fast path could in principle observe the pointer before the parsed contents are visible. The mutex_unlock() does not help such a reader given it only synchronizes with a later acquisition of the same lock. Thus, publish the pointer with smp_store_release() and read it on the fast path with smp_load_acquire(). Acquire semantics are needed rather than a dependency-ordered READ_ONCE(): btf_parse_vmlinux() also populates globals outside the returned object (e.g. bpf_ctx_convert.t). An address dependency would only order accesses performed through the pointer and not cover other globals.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
8580ac9404f6240668a026785d7d8856f0530409 to < f32a4a40bc635be25d6816da4bd91e9e58c31bf3affected8580ac9404f6240668a026785d7d8856f0530409 to < a7fe72d780122eb934536f1719abad445f6afdf7affected8580ac9404f6240668a026785d7d8856f0530409 to < e18a10b39c994f04e1ebd7f8fc042bb1ca8ad053affected8580ac9404f6240668a026785d7d8856f0530409 to < 978524ecfc1c539282df5858de1eec20748c6f74affected8580ac9404f6240668a026785d7d8856f0530409 to < eaf302628a78806f66d8224d6ba03fb4d5025de4affected8580ac9404f6240668a026785d7d8856f0530409 to < 2892f3f44bf865c8fb6b6c0960edec4cc91806eeaffected8580ac9404f6240668a026785d7d8856f0530409 to < 86d11c594d60b255b526fa5260f669463fb1a063affected8580ac9404f6240668a026785d7d8856f0530409 to < 92863e678070f57c17c868e4bfa2441a5c61ad2baffected
Linux Linux
Default version status: affected
5.5affected0 to < 5.5unaffected5.10.270 to ≤ 5.10.*unaffected5.15.221 to ≤ 5.15.*unaffected6.1.188 to ≤ 6.1.*unaffected6.6.157 to ≤ 6.6.*unaffected6.12.110 to ≤ 6.12.*unaffected6.18.52 to ≤ 6.18.*unaffected7.2.6 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/f32a4a40bc635be25d6816da4bd91e9e58c31bf3 ↗
- https://git.kernel.org/stable/c/a7fe72d780122eb934536f1719abad445f6afdf7 ↗
- https://git.kernel.org/stable/c/e18a10b39c994f04e1ebd7f8fc042bb1ca8ad053 ↗
- https://git.kernel.org/stable/c/978524ecfc1c539282df5858de1eec20748c6f74 ↗
- https://git.kernel.org/stable/c/eaf302628a78806f66d8224d6ba03fb4d5025de4 ↗
- https://git.kernel.org/stable/c/2892f3f44bf865c8fb6b6c0960edec4cc91806ee ↗
- https://git.kernel.org/stable/c/86d11c594d60b255b526fa5260f669463fb1a063 ↗
- https://git.kernel.org/stable/c/92863e678070f57c17c868e4bfa2441a5c61ad2b ↗