CVE-2026-31477 | In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix memory leaks and NULL deref in smb2_lock() smb2_lock() has three error handling issues after list_del() detaches smb_lock from lock_list at no_check_cl: 1) If vfs_lock_file() returns an unexpected error in the non-UNLOCK path, goto out leaks smb_lock and its flock because the out: handler only iterates lock_list and rollback_list, neither of which contains the detached
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix memory leaks and NULL deref in smb2_lock()
smb2_lock() has three error handling issues after list_del() detaches
smb_lock from lock_list at no_check_cl:
1) If vfs_lock_file() returns an unexpected error in the non-UNLOCK
path, goto out leaks smb_lock and its flock because the out:
handler only iterates lock_list and rollback_list, neither of
which contains the detached smb_lock.
2) If vfs_lock_file() returns -ENOENT in the UNLOCK path, goto out
leaks smb_lock and flock for the same reason. The error code
returned to the dispatcher is also stale.
3) In the rollback path, smb_flock_init() can return NULL on
allocation failure. The result is dereferenced unconditionally,
causing a kernel NULL pointer dereference. Add a NULL check to
prevent the crash and clean up the bookkeeping; the VFS lock
itself cannot be rolled back without the allocation and will be
released at file or connection teardown.
Fix cases 1 and 2 by hoisting the locks_free_lock()/kfree() to before
the if(!rc) check in the UNLOCK branch so all exit paths share one
free site, and by freeing smb_lock and flock before goto out in the
non-UNLOCK branch. Propagate the correct error code in both cases.
Fix case 3 by wrapping the VFS unlock in an if(rlock) guard and adding
a NULL check for locks_free_lock(rlock) in the shared cleanup.
Found via call-graph analysis using sqry.
- 🔗 git.kernel.org/stable/c/cdac6f7e7e428dc70e3b5898ac6999a7…
- 🔗 git.kernel.org/stable/c/c9b95ef6f5039f19e46c3a521a4fe175…
- 🔗 git.kernel.org/stable/c/91aeaa7256006d79a37298f5a1df2332…
- 🔗 git.kernel.org/stable/c/3cdacd11b41569ce75b3162142240f23…
- 🔗 git.kernel.org/stable/c/aab42f0795620cf0d3955a520f571f69…
- 🔗 git.kernel.org/stable/c/309b44ed684496ed3f9c5715d10b8993…
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CVE-2026-31477 | In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix memory leaks and NULL deref in smb2_lock() smb2_lock() has three error handling issues after list_del() detaches smb_lock from lock_list at no_check_cl: 1) If vfs_lock_file() returns an unexpected error in the non-UNLOCK path, goto out leaks smb_lock and its flock because the out: handler only iterates lock_list and rollback_list, neither of which contains the detached
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix memory leaks and NULL deref in smb2_lock() smb2_lock() has three error handling issues after list_del() detaches smb_lock from lock_list at no_check_cl: 1) If