Overview
About vulnerability
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.
Details
- Affected product:
- Debian 10 ELS , Debian 11 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+4 more)