CVE-2021-47353 udf: Fix NULL pointer dereference in udf_symlink function

What is CVE-2021-47353?

CVE-2021-47353 is a medium-severity vulnerability in Linux kernel, published on 21 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

udf: Fix NULL pointer dereference in udf_symlink function

In function udf_symlink, epos.bh is assigned with the value returned by udf_tgetblk. The function udf_tgetblk is defined in udf/misc.c and returns the value of sb_getblk function that could be NULL. Then, epos.bh is used without any check, causing a possible NULL pointer dereference when sb_getblk fails.

This fix adds a check to validate the value of epos.bh.

Weakness: CWE-476

Which versions are affected by CVE-2021-47353?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47353?

Apply the vendor's patch.

Is CVE-2021-47353 being exploited?

There is no known exploitation of CVE-2021-47353 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-2021-47353, GHSA-v5r4-g8jp-rvxf, UBUNTU-CVE-2021-47353.