scsi: target: reset t_task_cdb pointer in error case

[PATCH] scsi: target: reset t_task_cdb pointer in error case

Posted by Ваторопин Андрей 1 week, 6 days ago

From: Andrey Vatoropin <a.vatoropin@crpt.ru>

If allocation of cmd->t_task_cdb fails, it remains NULL but is later
dereferenced at the 'err' path.

In case of error reset NULL t_task_cdb value to point at the default
fixed-size buffer.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 9e95fb805dc0 ("scsi: target: Fix NULL pointer dereference")
Cc: stable@vger.kernel.org
Signed-off-by: Andrey Vatoropin <a.vatoropin@crpt.ru>
---
 drivers/target/target_core_transport.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 0a76bdfe5528..88544c911949 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1524,6 +1524,7 @@ target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb, gfp_t gfp)
 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb), gfp);
 		if (!cmd->t_task_cdb) {
+			cmd->t_task_cdb = &cmd->__t_task_cdb[0];
 			pr_err("Unable to allocate cmd->t_task_cdb"
 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
 				scsi_command_size(cdb),
-- 
2.43.0

Re: [PATCH] scsi: target: reset t_task_cdb pointer in error case

Posted by Mike Christie 1 week, 6 days ago

On 11/18/25 2:42 AM, Ваторопин Андрей wrote:
> From: Andrey Vatoropin <a.vatoropin@crpt.ru>
> 
> If allocation of cmd->t_task_cdb fails, it remains NULL but is later
> dereferenced at the 'err' path.
> 
> In case of error reset NULL t_task_cdb value to point at the default
> fixed-size buffer.
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 9e95fb805dc0 ("scsi: target: Fix NULL pointer dereference")
> Cc: stable@vger.kernel.org
> Signed-off-by: Andrey Vatoropin <a.vatoropin@crpt.ru>
> ---
>  drivers/target/target_core_transport.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
> index 0a76bdfe5528..88544c911949 100644
> --- a/drivers/target/target_core_transport.c
> +++ b/drivers/target/target_core_transport.c
> @@ -1524,6 +1524,7 @@ target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb, gfp_t gfp)
>  	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
>  		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb), gfp);
>  		if (!cmd->t_task_cdb) {
> +			cmd->t_task_cdb = &cmd->__t_task_cdb[0];
>  			pr_err("Unable to allocate cmd->t_task_cdb"
>  				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
>  				scsi_command_size(cdb),


Reviewed-by: Mike Christie <michael.christie@oracle.com>