Description (CNA)
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 (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 8580ac9404f6240668a026785d7d8856f0530409 before f32a4a40bc635be25d6816da4bd91e9e58c31bf3; affected 8580ac9404f6240668a026785d7d8856f0530409 before a7fe72d780122eb934536f1719abad445f6afdf7; affected 8580ac9404f6240668a026785d7d8856f0530409 before e18a10b39c994f04e1ebd7f8fc042bb1ca8ad053; affected 8580ac9404f6240668a026785d7d8856f0530409 before 978524ecfc1c539282df5858de1eec20748c6f74; affected 8580ac9404f6240668a026785d7d8856f0530409 before eaf302628a78806f66d8224d6ba03fb4d5025de4; affected 8580ac9404f6240668a026785d7d8856f0530409 before 2892f3f44bf865c8fb6b6c0960edec4cc91806ee; affected 8580ac9404f6240668a026785d7d8856f0530409 before 86d11c594d60b255b526fa5260f669463fb1a063; affected 8580ac9404f6240668a026785d7d8856f0530409 before 92863e678070f57c17c868e4bfa2441a5c61ad2b |
| Linux / Linux | affected 5.5; unaffected 0 before 5.5; unaffected 5.10.270 through 5.10.*; unaffected 5.15.221 through 5.15.*; unaffected 6.1.188 through 6.1.*; unaffected 6.6.157 through 6.6.*; unaffected 6.12.110 through 6.12.*; unaffected 6.18.52 through 6.18.*; unaffected 7.2.6 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.
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