[PATCH v2] mmc: vub300: fix invalid response handling

[Ulf Hansson]

On Sat, 13 May 2023 at 16:49, Deren Wu <deren.wu at mediatek.com> wrote:
>
> We may get an empty response with zero length at the beginning of
> the driver start and get following UBSAN error. Since there is no
> content(SDRT_NONE) for the response, just return and skip the response
> handling to avoid this problem.
>
> Test pass : SDIO wifi throughput test with this patch
>
> [  126.980684] UBSAN: array-index-out-of-bounds in drivers/mmc/host/vub300.c:1719:12
> [  126.980709] index -1 is out of range for type 'u32 [4]'
> [  126.980729] CPU: 4 PID: 9 Comm: kworker/u16:0 Tainted: G            E      6.3.0-rc4-mtk-local-202304272142 #1
> [  126.980754] Hardware name: Intel(R) Client Systems NUC8i7BEH/NUC8BEB, BIOS BECFL357.86A.0081.2020.0504.1834 05/04/2020
> [  126.980770] Workqueue: kvub300c vub300_cmndwork_thread [vub300]
> [  126.980833] Call Trace:
> [  126.980845]  <TASK>
> [  126.980860]  dump_stack_lvl+0x48/0x70
> [  126.980895]  dump_stack+0x10/0x20
> [  126.980916]  ubsan_epilogue+0x9/0x40
> [  126.980944]  __ubsan_handle_out_of_bounds+0x70/0x90
> [  126.980979]  vub300_cmndwork_thread+0x58e7/0x5e10 [vub300]
> [  126.981018]  ? _raw_spin_unlock+0x18/0x40
> [  126.981042]  ? finish_task_switch+0x175/0x6f0
> [  126.981070]  ? __switch_to+0x42e/0xda0
> [  126.981089]  ? __switch_to_asm+0x3a/0x80
> [  126.981129]  ? __pfx_vub300_cmndwork_thread+0x10/0x10 [vub300]
> [  126.981174]  ? __kasan_check_read+0x11/0x20
> [  126.981204]  process_one_work+0x7ee/0x13d0
> [  126.981246]  worker_thread+0x53c/0x1240
> [  126.981291]  kthread+0x2b8/0x370
> [  126.981312]  ? __pfx_worker_thread+0x10/0x10
> [  126.981336]  ? __pfx_kthread+0x10/0x10
> [  126.981359]  ret_from_fork+0x29/0x50
> [  126.981400]  </TASK>
>
> Fixes: 88095e7b473a ("mmc: Add new VUB300 USB-to-SD/SDIO/MMC driver")
> Signed-off-by: Deren Wu <deren.wu at mediatek.com>

Applied for fixes and by adding a stable tag, thanks!

Kind regards
Uffe


> ---
> v2: add Fixes tag
>     update commit description
> ---
>  drivers/mmc/host/vub300.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/mmc/host/vub300.c b/drivers/mmc/host/vub300.c
> index e4c4bfac3763..9ec593d52f0f 100644
> --- a/drivers/mmc/host/vub300.c
> +++ b/drivers/mmc/host/vub300.c
> @@ -1713,6 +1713,9 @@ static void construct_request_response(struct vub300_mmc_host *vub300,
>         int bytes = 3 & less_cmd;
>         int words = less_cmd >> 2;
>         u8 *r = vub300->resp.response.command_response;
> +
> +       if (!resp_len)
> +               return;
>         if (bytes == 3) {
>                 cmd->resp[words] = (r[1 + (words << 2)] << 24)
>                         | (r[2 + (words << 2)] << 16)
> --
> 2.18.0
>