Hi Jaegeuk,
I think the problem is that func ufshcd_read_desc_param() is not
expecting
one access unsupported descriptors on all W-LUs, not just RPMB LU.
If we can get the right buf_len from func
ufshcd_map_desc_id_to_length(),
the issue won't happen. -
https://lore.kernel.org/patchwork/patch/1323421/.
What do you think if we update ufshcd_map_desc_id_to_length(add one
param - desc_index)
so that it can tell the correct buf_len in case of W-LUs?
Thanks,
Can Guo.
On 2021-01-11 12:44, Jaegeuk Kim wrote:
From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
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@xxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 2a715f13fe1d..722697b57777 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3293,8 +3293,12 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
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;
+ if (param_offset + param_size > buff_len) {
+ if (buff_len > param_offset)
+ param_size = buff_len - param_offset;
+ else
+ param_size = 0;
+ }
memcpy(param_read_buf, &desc_buf[param_offset], param_size);
}
out:
