Re: [PATCH v3] scsi: pm8001: Fix use-after-free in pm8001_queue_command()

[Damien Le Moal <dlemoal@kernel.org>]

On 2/14/26 04:28, Salomon Dushimirimana wrote:
> Commit e29c47fe8946 ("scsi: pm8001: Simplify pm8001_task_exec()")
> refactors pm8001_queue_command(), however it introduces a potential
> cause of a double free scenario when it changes the function to return
> -ENODEV in case of phy down/device gone state.
> 
> In this path, pm8001_queue_command updates task status and calls
> task_done to indicate to upper layer that the task has been handled.
> However, this also frees the underlying sas task. A -ENODEV is then
> returned to the caller. When libsas sas_ata_qc_issue receives this error
> value, it assumes the task wasn't handled/queued by LLDD and proceeds to
> clean up and free the task again, resulting in a double free.
> 
> Since pm8001_queue_command handles the sas task in this case, it should
> return 0 to the caller indicating that the task has been handled.
> 
> Fixes: e29c47fe8946 ("scsi: pm8001: Simplify pm8001_task_exec()")
> Signed-off-by: Salomon Dushimirimana <salomondush@google.com>

Looks OK.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>


-- 
Damien Le Moal
Western Digital Research