NFSD: Prevent NULL dereference in nfsd4_process_cb_update()

Summary

In the Linux kernel, the following vulnerability has been resolved: NFSD: Prevent NULL dereference in nfsd4_process_cb_update() @ses is initialized to NULL. If __nfsd4_find_backchannel() finds no available backchannel session, setup_callback_client() will try to dereference @ses and segfault.

Timeline

1. Dec 27, 2024, 1:50 PM UTCCVE published
2. Oct 1, 2025, 8:03 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. Oct 15, 2026, 12:59 AM UTCRecord last updated

Affected versions

• Linux Linux

  From dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 · fixed in d9a0d1f6e15859ea7a86a327f28491e23deaaa62; From dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 · fixed in cac1405e3ff6685a438e910ad719e0cf06af90ee; From dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 · fixed in 752a75811f27300fe8131b0a1efc91960f6f88e7; From dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 · fixed in c5d90f9302742985a5078e42ac38de42c364c44a; From dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 · fixed in 0c3b0e326f838787d229314d4de83af9c53347e8; From dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 · fixed in eb51733ae5fc73d95bd857d5da26f9f65b202a79; From dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 · fixed in 03178cd8f67227015debb700123987fe96275cd1; From dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 · fixed in 4a4ffc1aa9d618e41ad9151f40966e402e58a5a2; From dcbeaa68dbbdacbbb330a86c7fc95a28473fc209 · fixed in 1e02c641c3a43c88cecc08402000418e15578d38

• Linux Linux

  2.6.38

• KernelLinux

  From 2.6.38 · fixed in 4.19.325; From 4.20.0 · fixed in 5.4.287; From 5.5.0 · fixed in 5.10.231; From 5.11.0 · fixed in 5.15.174; From 5.16.0 · fixed in 6.1.120; From 6.2.0 · fixed in 6.6.64; From 6.7.0 · fixed in 6.11.11; From 6.12.0 · fixed in 6.12.2

References 9