CVE-2026-45983

nfsd: never defer requests during idmap lookup

MEDIUM

5.5

CVSS Score

Published: May 27, 2026 at 12:18 PM UTC

Updated: June 17, 2026 at 10:52 AM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

MEDIUM5.5

Exploit prediction

EPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: never defer requests during idmap lookup During v4 request compound arg decoding, some ops (e.g. SETATTR) can trigger idmap lookup upcalls. When those upcall responses get delayed beyond the allowed time limit, cache_check() will mark the request for deferral and cause it to be dropped. This prevents nfs4svc_encode_compoundres from being executed, and thus the session slot flag NFSD4_SLOT_INUSE never gets cleared. Subsequent client requests will fail with NFSERR_JUKEBOX, given that the slot will be marked as in-use, making the SEQUENCE op fail. Fix this by making sure that the RQ_USEDEFERRAL flag is always clear during nfs4svc_decode_compoundargs(), since no v4 request should ever be deferred.

Affected

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

Linux Kernel · Linux

95%

2.6.30 ≤ v < 5.10.2522.6.30 ≤ v < 5.15.2022.6.30 ≤ v < 6.1.1652.6.30 ≤ v < 6.12.752.6.30 ≤ v < 6.18.142.6.30 ≤ v < 6.19.42.6.30 ≤ v < 6.6.1282.6.30 ≤ v < 7.05.11 ≤ v < 5.15.2025.16 ≤ v < 6.1.1656.13 ≤ v < 6.18.146.19 ≤ v < 6.19.46.2 ≤ v < 6.6.1286.7 ≤ v < 6.12.752.6.302f425878b6a71571341dcd3f9e9d1a6f6355da9c

Vendor states this is fixed in 063a6f22478ef929625000a2caf54667725c1dfd (fixed)

Vendor states this is fixed in 243f71ed873ff3feeb6f9b5cb145d63f7188b4c4 (fixed)

Vendor states this is fixed in 3a72c7dedc99b321e0f267e4e999e5baf07c4593 (fixed)

Vendor states this is fixed in 8dff54fe88c0dcd4c55bff9fc2fa6ca968290826 (fixed)

Vendor states this is fixed in 99e17b20fddac19a228d213e00f6b9e1c10daff9 (fixed)

Vendor states this is fixed in b9abb760db20504240a7147f27934d900cd80b23 (fixed)

Vendor states this is fixed in d75ec4504a4340b033b15cad0303988b3089dd93 (fixed)

Vendor states this is fixed in f9c206cdc4266caad6a9a7f46341420a10f03ccb (fixed)

Vendor states this is fixed in 2.6.30 (unaffected)

Vendor states this is fixed in 5.10.252 (unaffected)

Vendor states this is fixed in 5.15.202 (unaffected)

Vendor states this is fixed in 6.1.165 (unaffected)