CVE-2021-46952

NFS: fs_context: validate UDP retrans to prevent shift out-of-bounds

HIGH
7.1
CVSS Score
Published: February 27, 2024 at 06:40 PM UTC
Updated: June 17, 2026 at 04:15 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.1
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.11.0 ≤ v < 5.11.205.12.0 ≤ v < 5.12.35.6 ≤ v < 5.10.365.6 ≤ v < 5.11.205.6 ≤ v < 5.12.35.6 ≤ v < 5.135.6.0 ≤ v < 5.10.365.69954bf92c0cddd50a2a470be302e1c1ffdf21d42
Vendor states this is fixed in 2f3380121d49e829fb73ba86240c181bc32ad897 (fixed)
Vendor states this is fixed in 3d0163821c035040a46d816a42c0780f0f0a30a8 (fixed)
Vendor states this is fixed in 96fa26b74cdcf9f5c98996bf36bec9fb5b19ffe2 (fixed)
Vendor states this is fixed in c09f11ef35955785f92369e25819bf0629df2e59 (fixed)
Vendor states this is fixed in 5.10.36 (unaffected)
Vendor states this is fixed in 5.11.20 (unaffected)
Vendor states this is fixed in 5.12.3 (unaffected)
Vendor states this is fixed in 5.13 (unaffected)
Vendor states this is fixed in 5.6 (unaffected)

References (4)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/2f3380121d49e829fb73ba86240c181bc32ad897
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/3d0163821c035040a46d816a42c0780f0f0a30a8
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/96fa26b74cdcf9f5c98996bf36bec9fb5b19ffe2
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c09f11ef35955785f92369e25819bf0629df2e59

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-125

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