RE: [PATCH v3] scsi: ufs: WB is only available on LUN #0 to #7

[Avri Altman <Avri.Altman@wdc.com>]

> 
> 
> From: Jaegeuk Kim <jaegeuk@google.com>
> 
> Kernel stack violation when getting unit_descriptor/wb_buf_alloc_units from
> rpmb lun. The reason is the unit descriptor length is different per LU.
> 
> The lengh of Normal LU is 45, while the one of rpmb LU is 35.
> 
> int ufshcd_read_desc_param(struct ufs_hba *hba, ...)
> {
>         param_offset=41;
>         param_size=4;
>         buff_len=45;
>         ...
>         buff_len=35 by rpmb LU;
> 
>         if (is_kmalloc) {
>                 /* Make sure we don't copy more data than available */
>                 if (param_offset + param_size > buff_len)
>                         param_size = buff_len - param_offset;
>                         --> param_size = 250;
>                 memcpy(param_read_buf, &desc_buf[param_offset], param_size);
>                 --> memcpy(param_read_buf, desc_buf+41, 250);
> 
> [  141.868974][ T9174] Kernel panic - not syncing: stack-protector: Kernel
> stack is corrupted in: wb_buf_alloc_units_show+0x11c/0x11c
>         }
> }
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Reviewed-by: Avri Altman <avri.altman@wdc.com>