CVE-2021-47179: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.7% chance of exploitation in the next 30 days.

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.

Affected products

• Linux Linux Kernel: from 4.9.269, before 4.9.271 (fixed in 4.9.271); from 4.14.233, before 4.14.235 (fixed in 4.14.235); from 4.19.191, before 4.19.193 (fixed in 4.19.193); from 5.4.118, before 5.4.124 (fixed in 5.4.124); from 5.10.36, before 5.10.42 (fixed in 5.10.42); from 5.12.3, before 5.12.9 (fixed in 5.12.9)

Published 2024-03-25. Last modified 2026-08-04.