Re: [PATCH 6.1] scsi: ufs: ufshpb: Fix NULL deallocation in ufshpb_pre_req_mempool_destroy()

[Bart Van Assche <bvanassche@acm.org>]

On 7/3/24 4:17 AM, Aleksandr Mishin wrote:
> No upstream commit exists for this commit.
> 
> The issue was introduced with commit 41d8a9333cc9 ("scsi: ufs: ufshpb:
> Add HPB 2.0 support").
> 
> In ufshpb_pre_req_mempool_destroy() __free_page() is called only if pointer
> contains NULL value.
> Fix this bug by modifying check condition.
> 
> Upstream branch code has been significantly refactored and can't be
> backported directly.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 41d8a9333cc9 ("scsi: ufs: ufshpb: Add HPB 2.0 support")
> Signed-off-by: Aleksandr Mishin <amishin@t-argos.ru>
> ---
>   drivers/ufs/core/ufshpb.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/ufs/core/ufshpb.c b/drivers/ufs/core/ufshpb.c
> index b7f412d0f301..c649e8a10a23 100644
> --- a/drivers/ufs/core/ufshpb.c
> +++ b/drivers/ufs/core/ufshpb.c
> @@ -2120,7 +2120,7 @@ static void ufshpb_pre_req_mempool_destroy(struct ufshpb_lu *hpb)
>   	for (i = 0; i < hpb->throttle_pre_req; i++) {
>   		pre_req = hpb->pre_req + i;
>   		bio_put(hpb->pre_req[i].bio);
> -		if (!pre_req->wb.m_page)
> +		if (pre_req->wb.m_page)
>   			__free_page(hpb->pre_req[i].wb.m_page);
>   		list_del_init(&pre_req->list_req);
>   	}

Are any users of the 6.1 kernel using UFS HPB support? If not, another
possibility is to backport commit 7e9609d2daea ("scsi: ufs: core: Remove
HPB support").

Thanks,

Bart.