CVE-2025-40022
- Published: 2025-10-24T13:15:47.387
- Last modified: 1761571215
In the Linux kernel, the following vulnerability has been resolved:
crypto: af_alg – Fix incorrect boolean values in af_alg_ctx
Commit 1b34cbbf4f01 (“crypto: af_alg – Disallow concurrent writes in
af_alg_sendmsg”) changed some fields from bool to 1-bit bitfields of
type u32.
However, some assignments to these fields, specifically ‘more’ and
‘merge’, assign values greater than 1. These relied on C’s implicit
conversion to bool, such that zero becomes false and nonzero becomes
true.
With a 1-bit bitfields of type u32 instead, mod 2 of the value is taken
instead, resulting in 0 being assigned in some cases when 1 was intended.
Fix this by restoring the bool type.
Related CVE by CWE
No related CWE found.
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How to fix CVE-2025-40022
Description: In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg – Fix incorrect boolean values in af_alg_ctx Commit 1b34cbbf4f01 (“crypto: af_alg – Disallow concurrent writes in af_alg_sendmsg”) changed some fields from bool to 1-bit bitfields of type u32. However, some assignments to these fields, specifically ‘more’ and ‘merge’, assign values greater than 1. […]
Exploit Difficulty: HARD
⏱️ Time to exploit: > 4 hours
🛠️ Required skills: Advanced security expertise
💰 Public exploits: Rare or not public
How to Fix:
- Check if you're running the affected product
- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access
- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)
- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations
Exploit Difficulty Assessment
Vulnerability Timeline
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Detection Rules & IOCs
No specific detection rules generated for this vulnerability type.
No vendor/product data available.