nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr()

Summary

In the Linux kernel, the following vulnerability has been resolved: nfsd: add fh_want_write() for early-verified SETATTR in nfsd_proc_setattr() The BOTH_TIME_SET branch calls fh_verify() early so setattr_prepare() can inspect the dentry. This causes nfsd_setattr() to skip fh_want_write(), so notify_change() runs without a mount write reference. Add the missing fh_want_write() call after the early fh_verify().

Timeline

1. Sep 11, 2026, 7:46 PM UTCCVE published
2. Oct 16, 2026, 7:26 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Oct 19, 2026, 8:51 AM UTCRecord last updated

Affected versions

• Linux Linux

  From cc265089ce1b176dde963c74b53593446ee7f99a · fixed in 3eec9d791968c177a4a8cda9af5c04f79dae09cb; From cc265089ce1b176dde963c74b53593446ee7f99a · fixed in 9229d824b938f4fb0ea7a5dddade51735e6fe6f9; From cc265089ce1b176dde963c74b53593446ee7f99a · fixed in 2150305134889fb2fc25228d35353bd2f6f29500; From cc265089ce1b176dde963c74b53593446ee7f99a · fixed in d823bf9285cdf4514873b85ab5a888878dd4e8f4; From cc265089ce1b176dde963c74b53593446ee7f99a · fixed in 15ca3b64a69caa6194bed8f98a20ed90a11c11dd; From cc265089ce1b176dde963c74b53593446ee7f99a · fixed in 533964d420d385e11b08dd4c56c66ef5dcccaf08; From cc265089ce1b176dde963c74b53593446ee7f99a · fixed in c4a409b86a92815181a8e9395c6bf1696ad19175; From cc265089ce1b176dde963c74b53593446ee7f99a · fixed in 4e475be769aa9f7a2c1ce55a2b8592cfccacddcc; From 3.18.46 · fixed in 3.19

• Linux Linux

  4.2

• KernelLinux

  From 4.2.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.109; From 6.13.0 · fixed in 6.18.50; From 6.19.0 · fixed in 7.2.4

References 8