CVE-2026-74590
fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions
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.
INFO
Published Date :
Aug. 22, 2026, 4:16 p.m.
Last Modified :
Aug. 22, 2026, 4:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Use hash_alg->digest_size for stability.
- Widen dynptr_sz and out_digest_sz to u64.
- Apply the patch to the Linux kernel.
References to Advisories, Solutions, and Tools
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information, practical solutions, and valuable tools related to
CVE-2026-74590.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74590 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
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stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-74590
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-74590 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74590 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 22, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '67814c00de3161181cddd06c77aeaf86ac4cc584', 'lessThan': '1344b632cb5043e32939a84568125719111c5af3', 'versionType': 'git'}, {'status': 'affected', 'version': '67814c00de3161181cddd06c77aeaf86ac4cc584', 'lessThan': '2a5cfcad1d56e26d645b7887b0ed24c371851525', 'versionType': 'git'}, {'status': 'affected', 'version': '67814c00de3161181cddd06c77aeaf86ac4cc584', 'lessThan': '5bd63cad9df4328a184c409fbdad4f17944bcdb8', 'versionType': 'git'}, {'status': 'affected', 'version': '67814c00de3161181cddd06c77aeaf86ac4cc584', 'lessThan': '3e8ec7c0387273329374f5c7bd61f5f38af71fe1', 'versionType': 'git'}], 'programFiles': ['fs/verity/measure.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.8'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.8', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.104', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.45', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.9', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/verity/measure.c'], 'defaultStatus': 'affected'}] 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. Added Reference https://git.kernel.org/stable/c/1344b632cb5043e32939a84568125719111c5af3 Added Reference https://git.kernel.org/stable/c/2a5cfcad1d56e26d645b7887b0ed24c371851525 Added Reference https://git.kernel.org/stable/c/3e8ec7c0387273329374f5c7bd61f5f38af71fe1 Added Reference https://git.kernel.org/stable/c/5bd63cad9df4328a184c409fbdad4f17944bcdb8