CVE-2026-68312: cifs: fix cifsFileInfo leak on kmalloc failure in deferred close drain paths

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: 2026-08-10 · updated 2026-10-30

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: fix cifsFileInfo leak on kmalloc failure in deferred close drain paths In cifs_close_deferred_file(), cifs_close_all_deferred_files(), and cifs_close_deferred_file_under_dentry(), when a pending deferred close is cancelled via cancel_delayed_work(), the subsequent kmalloc_obj() to add the file to the local processing list may fail under memory pressure. The loop breaks immediately, but the cancelled work is no longer pending (it would have called _cifsFileInfo_put()), and the cfile is never added to file_head for processing. The cifsFileInfo reference and the open server handle both leak. Fix by saving the cfile that failed allocation in a local variable, breaking as before, and calling _cifsFileInfo_put() on it after releasing the lock. Any files later in the iteration are unaffected since their deferred work is still pending and will fire normally.

Affected products

Linux: 5.15 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux 7.2. Check the vendor advisory for mitigations.

References

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