CVE-2021-47179 NFSv4: Fix a NULL pointer dereference in pnfs_mark_matching_lsegs_return()

What is CVE-2021-47179?

CVE-2021-47179 is a high-severity vulnerability in Linux kernel, published on 25 Mar 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:

NFSv4: Fix a NULL pointer dereference in pnfs_mark_matching_lsegs_return()

Commit de144ff4234f changes _pnfs_return_layout() to call pnfs_mark_matching_lsegs_return() passing NULL as the struct pnfs_layout_range argument. Unfortunately, pnfs_mark_matching_lsegs_return() doesn't check if we have a value here before dereferencing it, causing an oops.

I'm able to hit this crash consistently when running connectathon basic tests on NFS v4.1/v4.2 against Ontap.

Weakness: CWE-476

Which versions are affected by CVE-2021-47179?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2021-47179?

Apply the vendor's patch.

Is CVE-2021-47179 being exploited?

There is no known exploitation of CVE-2021-47179 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-2021-47179, GHSA-w5g2-4rxc-h7x8, UBUNTU-CVE-2021-47179.