* [PATCH] nvmet: check sscanf value for subsys serial attr
@ 2019-11-21 20:31 Chaitanya Kulkarni
2019-11-26 16:50 ` Christoph Hellwig
0 siblings, 1 reply; 3+ messages in thread
From: Chaitanya Kulkarni @ 2019-11-21 20:31 UTC (permalink / raw)
To: linux-nvme; +Cc: Chaitanya Kulkarni
For nvmet in configfs.c we check return values for all the sscanf()
calls. Add similar check into the nvmet_subsys_attr_serial_store().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
drivers/nvme/target/configfs.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 98613a45bd3b..cc1fd36bf71e 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -853,12 +853,14 @@ static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,
const char *page, size_t count)
{
struct nvmet_subsys *subsys = to_subsys(item);
+ int ret = 0;
down_write(&nvmet_config_sem);
- sscanf(page, "%llx\n", &subsys->serial);
+ if (sscanf(page, "%llx\n", &subsys->serial) != 1)
+ ret = -EINVAL;
up_write(&nvmet_config_sem);
- return count;
+ return ret ? ret : count;
}
CONFIGFS_ATTR(nvmet_subsys_, attr_serial);
--
2.22.1
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] nvmet: check sscanf value for subsys serial attr
2019-11-21 20:31 [PATCH] nvmet: check sscanf value for subsys serial attr Chaitanya Kulkarni
@ 2019-11-26 16:50 ` Christoph Hellwig
2019-11-27 6:13 ` Chaitanya Kulkarni
0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2019-11-26 16:50 UTC (permalink / raw)
To: Chaitanya Kulkarni; +Cc: linux-nvme
On Thu, Nov 21, 2019 at 12:31:42PM -0800, Chaitanya Kulkarni wrote:
> For nvmet in configfs.c we check return values for all the sscanf()
> calls. Add similar check into the nvmet_subsys_attr_serial_store().
>
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> ---
> drivers/nvme/target/configfs.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
> index 98613a45bd3b..cc1fd36bf71e 100644
> --- a/drivers/nvme/target/configfs.c
> +++ b/drivers/nvme/target/configfs.c
> @@ -853,12 +853,14 @@ static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,
> const char *page, size_t count)
> {
> struct nvmet_subsys *subsys = to_subsys(item);
> + int ret = 0;
>
> down_write(&nvmet_config_sem);
> - sscanf(page, "%llx\n", &subsys->serial);
> + if (sscanf(page, "%llx\n", &subsys->serial) != 1)
> + ret = -EINVAL;
> up_write(&nvmet_config_sem);
>
> - return count;
> + return ret ? ret : count;
So the problem is that we've already possible corrupted subsys->serial
when an error occurs. So I think we need a local variable to sscan
in, return an error if that fails and only if it succeeds take the lock
and assign it to subsys->serial.
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linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] nvmet: check sscanf value for subsys serial attr
2019-11-26 16:50 ` Christoph Hellwig
@ 2019-11-27 6:13 ` Chaitanya Kulkarni
0 siblings, 0 replies; 3+ messages in thread
From: Chaitanya Kulkarni @ 2019-11-27 6:13 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-nvme
> So the problem is that we've already possible corrupted subsys->serial
> when an error occurs. So I think we need a local variable to sscan
> in, return an error if that fails and only if it succeeds take the lock
> and assign it to subsys->serial.
>
Okay, I'll send the V2.
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linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-11-21 20:31 [PATCH] nvmet: check sscanf value for subsys serial attr Chaitanya Kulkarni
2019-11-26 16:50 ` Christoph Hellwig
2019-11-27 6:13 ` Chaitanya Kulkarni
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