fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.12.104, 6.18.45, 7.1.9
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
In the Linux kernel, the following vulnerability has been resolved: fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions The BPF verifier and the dynptr abstraction ensure that the memory space referenced by a dynptr remains valid. They do not, however, provide any guarantee that the contents of the memory are stable. kfuncs are expected to remain memory-safe even if concurrent modifications occur. bpf_get_fsverity_digest() didn't follow that: it could crash if arg->digest_size was concurrently modified. Fix that by using the known-good value hash_alg->digest_size instead. Also widen 'dynptr_sz' and 'out_digest_sz' to u64 to match the return type of __bpf_dynptr_size(). It doesn't appear that it can actually be more than INT_MAX currently (since __bpf_dynptr_data_rw() excludes file-based pointers), but the correct type might as well be used.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From 67814c00de3161181cddd06c77aeaf86ac4cc584 · fixed in 1344b632cb5043e32939a84568125719111c5af3; From 67814c00de3161181cddd06c77aeaf86ac4cc584 · fixed in 2a5cfcad1d56e26d645b7887b0ed24c371851525; From 67814c00de3161181cddd06c77aeaf86ac4cc584 · fixed in 5bd63cad9df4328a184c409fbdad4f17944bcdb8; From 67814c00de3161181cddd06c77aeaf86ac4cc584 · fixed in 3e8ec7c0387273329374f5c7bd61f5f38af71fe1
- Linux Linux
6.8
- KernelLinux
From 6.8.0 · fixed in 6.12.104; From 6.13.0 · fixed in 6.18.45; From 6.19.0 · fixed in 7.1.9