On 2020-10-23 14:35, Daejun Park wrote:
Hi, Can Guo
Since WB feature has been added, WB related sysfs entries can be
accessed
even when an UFS device does not support WB feature. In that case, the
descriptors which are not supported by the UFS device may be wrongly
reported when they are accessed from their corrsponding sysfs entries.
Fix it by adding a sanity check of parameter offset against the actual
decriptor length.
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a2ebcc8..aeec10d 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3184,13 +3184,19 @@ int ufshcd_read_desc_param(struct ufs_hba
*hba,
/* Get the length of descriptor */
ufshcd_map_desc_id_to_length(hba, desc_id, &buff_len);
if (!buff_len) {
- dev_err(hba->dev, "%s: Failed to get desc length", __func__);
+ dev_err(hba->dev, "%s: Failed to get desc length\n", __func__);
+ return -EINVAL;
+ }
+
+ if (param_offset >= buff_len) {
+ dev_err(hba->dev, "%s: Invalid offset 0x%x in descriptor IDN 0x%x,
length 0x%x\n",
+ __func__, param_offset, desc_id, buff_len);
In my understanding, this code seems to check incorrect access to not
supportted features (e.g. WB) via buff_len value from
ufshcd_map_desc_id_to_length().
However, since buff_len is initialized as QUERY_DESC_MAX_SIZE and is
updated later by ufshcd_update_desc_length(), So it is impossible to
find
incorrect access by checking buff_len at first time.
Thanks,
Daejun
Yes, I considered that during bootup time, but the current driver won't
even
access WB related stuffs it is not supported (there are checks against
UFS version
and feature supports in ufshcd_wb_probe()). So this change is only
proecting illegal
access from sysfs entries after bootup is done. Do you see real error
during bootup
time? If yes, please let me know.
Thanks,
Can Guo.
