Re: [PATCH] fs: sysfs: Fix reference leak in sysfs_break_active_protection()

[Tejun Heo <tj@kernel.org>]

On Wed, Mar 13, 2024 at 05:43:41PM -0400, Alan Stern wrote:
> The sysfs_break_active_protection() routine has an obvious reference
> leak in its error path.  If the call to kernfs_find_and_get() fails then
> kn will be NULL, so the companion sysfs_unbreak_active_protection()
> routine won't get called (and would only cause an access violation by
> trying to dereference kn->parent if it was called).  As a result, the
> reference to kobj acquired at the start of the function will never be
> released.
> 
> Fix the leak by adding an explicit kobject_put() call when kn is NULL.
> 
> Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
> Fixes: 2afc9166f79b ("scsi: sysfs: Introduce sysfs_{un,}break_active_protection()")
> Cc: Bart Van Assche <bvanassche@acm.org>
> Cc: <stable@vger.kernel.org>

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun