CVE-2026-89642

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.