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: 88095e7b47 ("mmc: Add new VUB300 USB-to-SD/SDIO/MMC driver")
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/048cd6972c50c33c2e8f81d5228fed928519918b.1683987673.git.deren.wu@mediatek.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>