Re: [PATCH 3/3] scsi: mpi3mr: fix missing mrioc->evtack_cmds initialization

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 12/12/22 10:57, Shin'ichiro Kawasaki wrote:
> The commit c1af985d27da ("scsi: mpi3mr: Add Event acknowledgment logic")
> introduced an array mrioc->evtack_cmds. But initialization of the array
> elements was missed. They are just zero cleared. The function
> mpi3mr_complete_evt_ack refers host_tag field of the elements. Due to
> zero value of the host_tag field, the functions calls clear_bit for
> mrico->evtack_cmds_bitmap with wrong bit index. This results in memory
> access to invalid address and "BUG: KASAN: use-after-free". This BUG was
> observed at eHBA-9600 firmware update to version 8.3.1.0. To fix it, add
> the missing initialization of mrioc->evtack_cmds.
> 
> Fixes: c1af985d27da ("scsi: mpi3mr: Add Event acknowledgment logic")
> Cc: stable@vger.kernel.org
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>

Looks OK to me.

Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>


> ---
>  drivers/scsi/mpi3mr/mpi3mr_os.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
> index 3306de7170f6..6eaeba41072c 100644
> --- a/drivers/scsi/mpi3mr/mpi3mr_os.c
> +++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
> @@ -4952,6 +4952,10 @@ mpi3mr_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>  		mpi3mr_init_drv_cmd(&mrioc->dev_rmhs_cmds[i],
>  		    MPI3MR_HOSTTAG_DEVRMCMD_MIN + i);
>  
> +	for (i = 0; i < MPI3MR_NUM_EVTACKCMD; i++)
> +		mpi3mr_init_drv_cmd(&mrioc->evtack_cmds[i],
> +				    MPI3MR_HOSTTAG_EVTACKCMD_MIN + i);
> +
>  	if (pdev->revision)
>  		mrioc->enable_segqueue = true;
>  

-- 
Damien Le Moal
Western Digital Research