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

What is CVE-2021-47307?

CVE-2021-47307 is a high-severity vulnerability in Linux kernel, published on 21 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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")

Weakness: CWE-476

Which versions are affected by CVE-2021-47307?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47307?

Apply the vendor's patch.

Is CVE-2021-47307 being exploited?

There is no known exploitation of CVE-2021-47307 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-47307, GHSA-c9p5-rxmf-r4m6, UBUNTU-CVE-2021-47307.