[PATCH] qedi: Fix a potential buffer overflow

[PATCH] qedi: Fix a potential buffer overflow

[Bart Van Assche]

Tell snprintf() to store at most 255 characters in the output buffer
instead of 256. This patch avoids that smatch reports the following
warning:

drivers/scsi/qedi/qedi_main.c:891: qedi_get_boot_tgt_info() error: snprintf() is printing too much 256 vs 255

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: <QLogic-Storage-Upstream@cavium.com>
Cc: <stable@vger.kernel.org>
---
 drivers/scsi/qedi/qedi_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
index 682f3ce31014..ea62180d9ec8 100644
--- a/drivers/scsi/qedi/qedi_main.c
+++ b/drivers/scsi/qedi/qedi_main.c
@@ -888,7 +888,7 @@ static void qedi_get_boot_tgt_info(struct nvm_iscsi_block *block,
 	ipv6_en = !!(block->generic.ctrl_flags &
 		     NVM_ISCSI_CFG_GEN_IPV6_ENABLED);
 
-	snprintf(tgt->iscsi_name, NVM_ISCSI_CFG_ISCSI_NAME_MAX_LEN, "%s\n",
+	snprintf(tgt->iscsi_name, sizeof(tgt->iscsi_name), "%s\n",
 		 block->target[index].target_name.byte);
 
 	tgt->ipv6_en = ipv6_en;
-- 
2.18.0

Re: [PATCH] qedi: Fix a potential buffer overflow

[Javali, Nilesh]

On 7/27/18, 2:40 AM, "Bart Van Assche" <bart.vanassche@wdc.com> wrote:

>External Email
>
>Tell snprintf() to store at most 255 characters in the output buffer
>instead of 256. This patch avoids that smatch reports the following
>warning:
>
>drivers/scsi/qedi/qedi_main.c:891: qedi_get_boot_tgt_info() error:
>snprintf() is printing too much 256 vs 255
>
>Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
>Cc: <QLogic-Storage-Upstream@cavium.com>
>Cc: <stable@vger.kernel.org>
>---
> drivers/scsi/qedi/qedi_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/drivers/scsi/qedi/qedi_main.c b/drivers/scsi/qedi/qedi_main.c
>index 682f3ce31014..ea62180d9ec8 100644
>--- a/drivers/scsi/qedi/qedi_main.c
>+++ b/drivers/scsi/qedi/qedi_main.c
>@@ -888,7 +888,7 @@ static void qedi_get_boot_tgt_info(struct
>nvm_iscsi_block *block,
>        ipv6_en = !!(block->generic.ctrl_flags &
>                     NVM_ISCSI_CFG_GEN_IPV6_ENABLED);
>
>-       snprintf(tgt->iscsi_name, NVM_ISCSI_CFG_ISCSI_NAME_MAX_LEN,
>"%s\n",
>+       snprintf(tgt->iscsi_name, sizeof(tgt->iscsi_name), "%s\n",
>                 block->target[index].target_name.byte);
>
>        tgt->ipv6_en = ipv6_en;
>--
>2.18.0
>

Thanks,

Acked-by: Nilesh Javali <nilesh.javali@cavium.com>

Re: [PATCH] qedi: Fix a potential buffer overflow

[Martin K. Petersen]

Bart,

> Tell snprintf() to store at most 255 characters in the output buffer
> instead of 256. This patch avoids that smatch reports the following
> warning:

Applied to 4.18/scsi-fixes. Thank you!

-- 
Martin K. Petersen	Oracle Linux Engineering