What’s Vulnerable › Vulnerabilities

CVE-2017-18221

• Severity: medium (CVSS 5.5 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-03-07 · updated 2026-06-17
• Weakness: CWE-20

Description

The __munlock_pagevec function in mm/mlock.c in the Linux kernel before 4.11.4 allows local users to cause a denial of service (NR_MLOCK accounting corruption) via crafted use of mlockall and munlockall system calls.

Affected products

• Linux kernel: before 4.11.4 — fixed in 4.11.4

How to fix

Upgrade to a fixed version: Linux kernel 4.11.4. Check the vendor advisory for mitigations.

References

• http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=70feee0e1ef331b22cc51f383d532a0d043fbdcc
• http://www.securityfocus.com/bid/103321
• https://github.com/torvalds/linux/commit/70feee0e1ef331b22cc51f383d532a0d043fbdcc
• https://usn.ubuntu.com/3655-1/
• https://usn.ubuntu.com/3655-2/
• https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.11.4
• http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=70feee0e1ef331b22cc51f383d532a0d043fbdcc
• http://www.securityfocus.com/bid/103321
• https://github.com/torvalds/linux/commit/70feee0e1ef331b22cc51f383d532a0d043fbdcc
• https://usn.ubuntu.com/3655-1/
• https://usn.ubuntu.com/3655-2/
• https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.11.4

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