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.
History

Sat, 22 Aug 2026 19:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-847

Sat, 22 Aug 2026 15:45:00 +0000

Type Values Removed Values Added
Description 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.
Title fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-22T15:31:41.929Z

Reserved: 2026-08-15T05:44:03.918Z

Link: CVE-2026-74590

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-22T16:16:31.243

Modified: 2026-08-22T16:16:31.243

Link: CVE-2026-74590

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-22T19:30:17Z