On 10.08.21 06:04, Tuo Li wrote:
The return value of transport_kmap_data_sg() is assigned to the variable
buf:
buf = transport_kmap_data_sg(cmd);
And then it is checked:
if (!buf) {
This indicates that buf can be NULL. However, it is dereferenced in the
following statements:
if (!(buf[3] & 0x80))
buf[3] |= 0x80;
if (!(buf[2] & 0x80))
buf[2] |= 0x80;
To fix these possible null-pointer dereferences, dereference buf and call
transport_kunmap_data_sg() only when buf is not NULL.
Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>
Signed-off-by: Tuo Li <islituo@xxxxxxxxx>
---
v2:
* Put transport_kunmap_data_sg() into the else-branch of the if (!bug).
Thank Bodo Stroesser for helpful advice.
---
drivers/target/target_core_pscsi.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 2629d2ef3970..75ef52f008ff 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -620,17 +620,17 @@ static void pscsi_complete_cmd(struct se_cmd *cmd, u8 scsi_status,
buf = transport_kmap_data_sg(cmd);
if (!buf) {
; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
- }
-
- if (cdb[0] == MODE_SENSE_10) {
- if (!(buf[3] & 0x80))
- buf[3] |= 0x80;
} else {
- if (!(buf[2] & 0x80))
- buf[2] |= 0x80;
- }
+ if (cdb[0] == MODE_SENSE_10) {
+ if (!(buf[3] & 0x80))
+ buf[3] |= 0x80;
+ } else {
+ if (!(buf[2] & 0x80))
+ buf[2] |= 0x80;
+ }
- transport_kunmap_data_sg(cmd);
+ transport_kunmap_data_sg(cmd);
+ }
}
}
after_mode_sense:
Reviewed-by: Bodo Stroesser <bostroesser@xxxxxxxxx>
Regards,
Bodo
