CVE-2026-89697

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().

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxcc265089ce1b176dde963c74b53593446ee7f99a < 15ca3b64a69caa6194bed8f98a20ed90a11c11ddaffected
LinuxLinuxcc265089ce1b176dde963c74b53593446ee7f99a < 533964d420d385e11b08dd4c56c66ef5dcccaf08affected
LinuxLinuxcc265089ce1b176dde963c74b53593446ee7f99a < c4a409b86a92815181a8e9395c6bf1696ad19175affected
LinuxLinuxcc265089ce1b176dde963c74b53593446ee7f99a < 4e475be769aa9f7a2c1ce55a2b8592cfccacddccaffected
LinuxLinux1cb57d81cf20fe24b9e2e1daf57bfbdc24b77cd8affected
LinuxLinux3.18.46 < 3.19affected
LinuxLinux4.2affected
LinuxLinux0 < 4.2unaffected
LinuxLinux6.12.109 <= 6.12.*unaffected
LinuxLinux6.18.50 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References