* [PATCH v2] scsi: target: pscsi: Fix possible null-pointer dereference in pscsi_complete_cmd()
@ 2021-08-10 4:04 Tuo Li
2021-08-10 7:18 ` Bodo Stroesser
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Tuo Li @ 2021-08-10 4:04 UTC (permalink / raw)
To: martin.petersen
Cc: linux-scsi, target-devel, linux-kernel, baijiaju1990, Tuo Li, TOTE Robot
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@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
---
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:
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] scsi: target: pscsi: Fix possible null-pointer dereference in pscsi_complete_cmd()
2021-08-10 4:04 [PATCH v2] scsi: target: pscsi: Fix possible null-pointer dereference in pscsi_complete_cmd() Tuo Li
@ 2021-08-10 7:18 ` Bodo Stroesser
2021-08-17 2:55 ` Martin K. Petersen
2021-08-24 4:02 ` Martin K. Petersen
2 siblings, 0 replies; 4+ messages in thread
From: Bodo Stroesser @ 2021-08-10 7:18 UTC (permalink / raw)
To: Tuo Li, martin.petersen
Cc: linux-scsi, target-devel, linux-kernel, baijiaju1990, TOTE Robot
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@tsinghua.edu.cn>
> Signed-off-by: Tuo Li <islituo@gmail.com>
> ---
> 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@gmail.com>
Regards,
Bodo
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] scsi: target: pscsi: Fix possible null-pointer dereference in pscsi_complete_cmd()
2021-08-10 4:04 [PATCH v2] scsi: target: pscsi: Fix possible null-pointer dereference in pscsi_complete_cmd() Tuo Li
2021-08-10 7:18 ` Bodo Stroesser
@ 2021-08-17 2:55 ` Martin K. Petersen
2021-08-24 4:02 ` Martin K. Petersen
2 siblings, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2021-08-17 2:55 UTC (permalink / raw)
To: Tuo Li
Cc: martin.petersen, linux-scsi, target-devel, linux-kernel,
baijiaju1990, TOTE Robot
Tuo,
> The return value of transport_kmap_data_sg() is assigned to the variable
> buf:
Applied to 5.15/scsi-staging, thanks!
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] scsi: target: pscsi: Fix possible null-pointer dereference in pscsi_complete_cmd()
2021-08-10 4:04 [PATCH v2] scsi: target: pscsi: Fix possible null-pointer dereference in pscsi_complete_cmd() Tuo Li
2021-08-10 7:18 ` Bodo Stroesser
2021-08-17 2:55 ` Martin K. Petersen
@ 2021-08-24 4:02 ` Martin K. Petersen
2 siblings, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2021-08-24 4:02 UTC (permalink / raw)
To: Tuo Li
Cc: Martin K . Petersen, target-devel, linux-kernel, linux-scsi,
TOTE Robot, baijiaju1990
On Mon, 9 Aug 2021 21:04:13 -0700, 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) {
>
> [...]
Applied to 5.15/scsi-queue, thanks!
[1/1] scsi: target: pscsi: Fix possible null-pointer dereference in pscsi_complete_cmd()
https://git.kernel.org/mkp/scsi/c/0f99792c01d1
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-08-10 4:04 [PATCH v2] scsi: target: pscsi: Fix possible null-pointer dereference in pscsi_complete_cmd() Tuo Li
2021-08-10 7:18 ` Bodo Stroesser
2021-08-17 2:55 ` Martin K. Petersen
2021-08-24 4:02 ` Martin K. Petersen
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