CVE-2015-5706

Severity: medium (CVSS 4.6 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2015-08-31 · updated 2026-06-17
Weakness: CWE-416

Description

Use-after-free vulnerability in the path_openat function in fs/namei.c in the Linux kernel 3.x and 4.x before 4.0.4 allows local users to cause a denial of service or possibly have unspecified other impact via O_TMPFILE filesystem operations that leverage a duplicate cleanup operation.

Affected products

Canonical Ubuntu Linux: 12.04, 14.04
Debian Linux: 7.0, 8.0
Linux kernel: from 3.0 through 3.19.8; from 4.0 before 4.0.4 — fixed in 4.0.4

How to fix

Upgrade to a fixed version: Linux kernel 4.0.4. Check the vendor advisory for mitigations.

References

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f15133df088ecadd141ea1907f2c96df67c729f0
http://twitter.com/grsecurity/statuses/597127122910490624
http://www.debian.org/security/2015/dsa-3329
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.0.4
http://www.openwall.com/lists/oss-security/2015/08/01/5
http://www.securityfocus.com/bid/76142
http://www.ubuntu.com/usn/USN-2680-1
http://www.ubuntu.com/usn/USN-2681-1
https://bugzilla.redhat.com/show_bug.cgi?id=1250047
https://github.com/torvalds/linux/commit/f15133df088ecadd141ea1907f2c96df67c729f0
https://source.android.com/security/bulletin/2017-01-01.html
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f15133df088ecadd141ea1907f2c96df67c729f0

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