What’s Vulnerable › Vulnerabilities

CVE-2026-89642: cifs: call pagecache_isize_extended() in cifs_setsize() when extending

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-11 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: call pagecache_isize_extended() in cifs_setsize() when extending cifs_setsize() calls truncate_pagecache() but skips pagecache_isize_extended() on extension. truncate_setsize() shows the correct pattern: i_size_write(inode, newsize); if (newsize > oldsize) pagecache_isize_extended(inode, oldsize, newsize); truncate_pagecache(inode, newsize); pagecache_isize_extended() zeroes the tail of the page straddling old EOF. Without it, dirty bytes in that region can be written back to the server, exposing stale data in the newly extended range.

Affected products

• Linux: 2.6.12 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/12bafe32f09c0d24f5096154b59c347b9c6606e0
• https://git.kernel.org/stable/c/40c16040783abcc240bd1b453e679ea6ca30e19e
• https://git.kernel.org/stable/c/5463d96cd2e46064ceefcf861b028745a4f4c373
• https://git.kernel.org/stable/c/880e1b5883a5d78d916fa446791c48f28a16719b
• https://git.kernel.org/stable/c/c510edb9734af1c274d18f4f31a471a166bbc7e8
• https://git.kernel.org/stable/c/e1f692b6da3e632a25d0b3a99f833bb609bae1a3

Get alerted when CVE-2026-89642 or the next vulnerability affects your stack