CVE-2022-49281: cifs: fix handlecache and multiuser
In the Linux kernel, the following vulnerability has been resolved:
cifs: fix handlecache and multiuser
In multiuser each individual user has their own tcon structure for the share and thus their own handle for a cached directory. When we umount such a share we much make sure to release the pinned down dentry for each such tcon and not just the master tcon.
Otherwise we will get nasty warnings on umount that dentries are still in use: [ 3459.590047] BUG: Dentry 00000000115c6f41{i=12000000019d95,n=/} still in use\ (2) [unmount of cifs cifs] ... [ 3459.590492] Call Trace: [ 3459.590500] dwalk+0x61/0x2a0 [ 3459.590518] ? shrinklockdentry.part.0+0xe0/0xe0 [ 3459.590526] shrinkdcacheforumount+0x49/0x110 [ 3459.590535] genericshutdownsuper+0x1a/0x110 [ 3459.590542] killanonsuper+0x14/0x30 [ 3459.590549] cifskillsb+0xf5/0x104 [cifs] [ 3459.590773] deactivatelockedsuper+0x36/0xa0 [ 3459.590782] cleanupmnt+0x131/0x190 [ 3459.590789] taskworkrun+0x5c/0x90 [ 3459.590798] exittousermodeloop+0x151/0x160 [ 3459.590809] exittousermodeprepare+0x83/0xd0 [ 3459.590818] syscallexittousermode+0x12/0x30 [ 3459.590828] dosyscall64+0x48/0x90 [ 3459.590833] entrySYSCALL64afterhwframe+0x44/0xae
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2022-49281?
CVE-2022-49281 has been classified as a medium-severity vulnerability affecting the Linux kernel.
How do I fix CVE-2022-49281?
To fix CVE-2022-49281, it is recommended to update the Linux kernel to the patched version available from your distribution.
What component is affected by CVE-2022-49281?
CVE-2022-49281 affects the Linux CIFS (Common Internet File System) implementation within the Linux kernel.
Can CVE-2022-49281 lead to data leakage?
Yes, CVE-2022-49281 can potentially lead to data leakage by improperly managing handles for cached directories in multiuser scenarios.
Is CVE-2022-49281 present in all Linux kernel versions?
CVE-2022-49281 is not present in all Linux kernel versions; it is specific to versions prior to the fix which addresses the multiuser caching issue.