CVE-2015-7550

Severity: medium (CVSS 5.5 v3.0)
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: 2016-02-08 · updated 2026-06-17
Weakness: CWE-362

Description

The keyctl_read_key function in security/keys/keyctl.c in the Linux kernel before 4.3.4 does not properly use a semaphore, which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via a crafted application that leverages a race condition between keyctl_revoke and keyctl_read calls.

Affected products

Linux kernel: through 4.3.3

References

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b4a1b4f5047e4f54e194681125c74c0aa64d637d
http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00094.html
http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00045.html
http://lists.opensuse.org/opensuse-security-announce/2016-08/msg00038.html
http://www.debian.org/security/2016/dsa-3434
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.3.4
http://www.securityfocus.com/bid/79903
http://www.ubuntu.com/usn/USN-2888-1
http://www.ubuntu.com/usn/USN-2890-1
http://www.ubuntu.com/usn/USN-2890-2
http://www.ubuntu.com/usn/USN-2890-3
http://www.ubuntu.com/usn/USN-2911-1

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