smb: client: fix cifsFileInfo reference leak in deferred close
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.6.160, 6.12.113, 6.18.54, 7.2.7
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix cifsFileInfo reference leak in deferred close When cifs_close() defers a close, it hands the cifsFileInfo reference of the closing struct file to the queued work. Each execution of smb2_deferred_work_close() drops one such reference. deferred_close_scheduled can be false while the work is pending: the workqueue clears PENDING when the callback starts to run, before the callback clears the flag under deferred_lock. A close in that interval requeues the running work, and the callback then clears the flag, leaving the requeued work pending with the flag down. A later cifs_open() can reuse the handle and its cifs_close() reaches the same branch: queue_delayed_work() fails because the work is still pending, but cifs_close() returns without dropping the closing file's reference. The cifsFileInfo count stays pinned and its tlink, dentry and server handle are leaked. Check the return value and hand off the reference only when work was actually queued. Otherwise, use the shared _cifsFileInfo_put(), like the mod_delayed_work() branch above: the pending execution already owns its reference. This issue was found by an in-house static analysis tool.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From c3f207ab29f793b8c942ce8067ed123f18d5b81b · fixed in 525c225e23d61694091f2806de553a69362a78ff; From c3f207ab29f793b8c942ce8067ed123f18d5b81b · fixed in bbeb7a42c9ea656e17ddcbdc2d7917aa853383a6; From c3f207ab29f793b8c942ce8067ed123f18d5b81b · fixed in a6767712902beb0f53238be485971c9a83ea1079; From c3f207ab29f793b8c942ce8067ed123f18d5b81b · fixed in ea93759d6c2789924f4e557aed5be532207715ea; From c3f207ab29f793b8c942ce8067ed123f18d5b81b · fixed in 5520e89a5a4f834bced64cf2ac927001cc513a40
- Linux Linux
5.13
- KernelLinux
From 5.13.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.113; From 6.13.0 · fixed in 6.18.54; From 6.19.0 · fixed in 7.2.7