# CVE-2021-46952: linux: In the Linux kernel, the following vulnerability has been resolved:  NFS: fs_context: validate UDP retrans to prevent...

CVE-2021-46952 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-46952, released February 27, 2024. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-46952
- Priority: High
- CVSS: 7.1 (high)
- EPSS: 0.0028
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 27, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  NFS: fs_context: validate UDP retrans to prevent shift out-of-bounds  Fix shift out-of-bounds in xprt_calc_majortimeo(). This is caused by a garbage timeout (retrans) mount option being passed to nfs mount, in this case from syzkaller.  If the protocol is XPRT_TRANSPORT_UDP, then 'retrans' is a shift value for a 64-bit long integer, so 'retrans' cannot be >= 64. If it is >= 64, fail the mount and return an error.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.10.38-1 | [DEBIAN-CVE-2021-46952](https://patchblox.com/security/data/fix/linux/debian-cve-2021-46952.md) | Feb 27, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.10.38-1 | [DEBIAN-CVE-2021-46952](https://patchblox.com/security/data/fix/linux/debian-cve-2021-46952.md) | Feb 27, 2024 |
| Linux | linux Debian 14 | 5.10.38-1 | [DEBIAN-CVE-2021-46952](https://patchblox.com/security/data/fix/linux/debian-cve-2021-46952.md) | Feb 27, 2024 |

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