CVE-2026-45983

nfsd: never defer requests during idmap lookup

State: Published
Severity: Not scored
Published: May 27, 2026
Updated: May 27, 2026
Reserved: May 13, 2026

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.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before b9abb760db20504240a7147f27934d900cd80b23Affected 2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 3a72c7dedc99b321e0f267e4e999e5baf07c4593Affected 2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 99e17b20fddac19a228d213e00f6b9e1c10daff9Affected 2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 243f71ed873ff3feeb6f9b5cb145d63f7188b4c4Affected 2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 063a6f22478ef929625000a2caf54667725c1dfdAffected 2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before d75ec4504a4340b033b15cad0303988b3089dd93Affected 2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 8dff54fe88c0dcd4c55bff9fc2fa6ca968290826Affected 2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before f9c206cdc4266caad6a9a7f46341420a10f03ccbAffected
LinuxLinux	2.6.30Affected before 2.6.30Not affected 5.10.252 through 5.10.Not affected 5.15.202 through 5.15.Not affected 6.1.165 through 6.1.Not affected 6.6.128 through 6.6.Not affected 6.12.75 through 6.12.Not affected 6.18.14 through 6.18.Not affected 6.19.4 through 6.19.*Not affected 7.0 and laterNot affected

Product

Versions

LinuxLinux

2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before b9abb760db20504240a7147f27934d900cd80b23Affected
2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 3a72c7dedc99b321e0f267e4e999e5baf07c4593Affected
2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 99e17b20fddac19a228d213e00f6b9e1c10daff9Affected
2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 243f71ed873ff3feeb6f9b5cb145d63f7188b4c4Affected
2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 063a6f22478ef929625000a2caf54667725c1dfdAffected
2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before d75ec4504a4340b033b15cad0303988b3089dd93Affected
2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before 8dff54fe88c0dcd4c55bff9fc2fa6ca968290826Affected
2f425878b6a71571341dcd3f9e9d1a6f6355da9c to before f9c206cdc4266caad6a9a7f46341420a10f03ccbAffected

LinuxLinux

2.6.30Affected
before 2.6.30Not affected
5.10.252 through 5.10.*Not affected
5.15.202 through 5.15.*Not affected
6.1.165 through 6.1.*Not affected
6.6.128 through 6.6.*Not affected
6.12.75 through 6.12.*Not affected
6.18.14 through 6.18.*Not affected
6.19.4 through 6.19.*Not affected
7.0 and laterNot affected

References

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