What’s Vulnerable › Vulnerabilities

CVE-2021-47307: cifs: prevent NULL deref in cifs_compose_mount_options()

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-05-21 · updated 2026-08-04
• Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: prevent NULL deref in cifs_compose_mount_options() The optional @ref parameter might contain an NULL node_name, so prevent dereferencing it in cifs_compose_mount_options(). Addresses-Coverity: 1476408 ("Explicit null dereferenced")

Affected products

• Linux kernel: before 5.4.135; from 5.5 before 5.10.53; from 5.11 before 5.13.5 — fixed in 5.10.53, 5.13.5, 5.4.135

How to fix

Upgrade to a fixed version: Linux kernel 5.10.53, 5.13.5, 5.4.135. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/03313d1c3a2f086bb60920607ab79ac8f8578306
• https://git.kernel.org/stable/c/ae3d181f4e912f51af7776ea165f199b16fc165d
• https://git.kernel.org/stable/c/e58c162789becede894d3e94c0ce6695a2ef5796
• https://git.kernel.org/stable/c/f7d1fa65e74263d11f90ddd33b4d4cd905a93759
• https://git.kernel.org/stable/c/03313d1c3a2f086bb60920607ab79ac8f8578306
• https://git.kernel.org/stable/c/ae3d181f4e912f51af7776ea165f199b16fc165d
• https://git.kernel.org/stable/c/e58c162789becede894d3e94c0ce6695a2ef5796
• https://git.kernel.org/stable/c/f7d1fa65e74263d11f90ddd33b4d4cd905a93759

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