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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.6 | 5.10.36 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 5.10.38-1 | — |
| Debian 13 | linux | 5.10.38-1 | — |
| Debian 12 | linux | 5.10.38-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | linux-riscv +20 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +26 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Advisories 1
- WID-SEC-2024-0508 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Oct 30, 2025