#VU11852 NULL pointer dereference/Race condition in Linux kernel - CVE-2015-7550

Vulnerability identifier: #VU11852

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2015-7550

CWE-ID: CWE-362

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description
The vulnerability allows a local attacker to cause DoS condition on the target system.

The weakness in the keyctl_read_key function in security/keys/keyctl.c due to improper use of a semaphore. A local attacker can submit a specially crafted application that leverages a race condition between keyctl_revoke and keyctl_read calls, trigger NULL pointer dereference and cause the service o crash.

Mitigation
Update to version 4.3.4.

Vulnerable software versions

Linux kernel: 4.3 - 4.3.3

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External links
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4a1b4f5047e4f54e19468...

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.