Re: [PATCH] HID: hidraw: fix a problem of memory leak in hidraw_release()

[Dan Carpenter]

On Thu, Jan 25, 2024 at 02:32:26PM +0800, Su Hui wrote:
> 'struct hidraw_list' is a circular queue whose head can be smaller than
> tail. Using 'list->tail != list->head' to release all memory that should
> be released.
> 
> Fixes: a5623a203cff ("HID: hidraw: fix memory leak in hidraw_release()")
> Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>

This is very clever.  How did you find that?  Was it through static
analysis or just review?  Perhaps using syzkaller?

Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

I imagine we could write a checker heuristic to identify ->tail and
->head struct members and then complain if they were ever used in a <
or > comparison.

regards,
dan carpenter