What’s Vulnerable › Vulnerabilities

CVE-2026-43109: x86: shadow stacks: proper error handling for mmap lock

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-06 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: x86: shadow stacks: proper error handling for mmap lock 김영민 reports that shstk_pop_sigframe() doesn't check for errors from mmap_read_lock_killable(), which is a silly oversight, and also shows that we haven't marked those functions with "__must_check", which would have immediately caught it. So let's fix both issues.

Affected products

• Linux kernel: from 6.6 before 6.18.24; from 6.19 before 6.19.14; 7.0-rc1, 7.0-rc2, 7.0-rc3, 7.0-rc4, 7.0-rc5, 7.0-rc6 (+1) — fixed in 6.18.24, 6.19.14

How to fix

Upgrade to a fixed version: Linux kernel 6.18.24, 6.19.14. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/1a30468eff661937d978495644d2e5ebfeef5ce6
• https://git.kernel.org/stable/c/262b6d38a81d51b135db81e1f30c13d30e38feee
• https://git.kernel.org/stable/c/52f657e34d7b21b47434d9d8b26fa7f6778b63a0
• https://git.kernel.org/stable/c/c64cebcc5c4f223dbcbe7dcdf74908fc092a0aa4
• https://git.kernel.org/stable/c/c79cf42321600e931933e11f94aba8b245d4cd66

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