Linux-NVDIMM Archive on lore.kernel.org
 help / color / Atom feed
* [ndctl PATCH] libndctl: Fix a potentially non NUL-terminated string operation
@ 2019-09-20 18:06 Vishal Verma
  2019-09-20 18:14 ` Dave Jiang
  0 siblings, 1 reply; 2+ messages in thread
From: Vishal Verma @ 2019-09-20 18:06 UTC (permalink / raw)
  To: linux-nvdimm

Static analysis warns that pread() doesn't NUL-terminate buffers, and
that we shouldn't pass it directly to strcmp. The sysfs string should
normally have the right termination, but for correctness in the library,
we shouldn't rely on that. Replace the strcmp() calls in question with
an explicit strncmp().

Fixes: 3c0c7db045ec ("ndctl: add a wait-overwrite command")
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 ndctl/lib/dimm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ndctl/lib/dimm.c b/ndctl/lib/dimm.c
index 2f145be..17344f0 100644
--- a/ndctl/lib/dimm.c
+++ b/ndctl/lib/dimm.c
@@ -825,7 +825,7 @@ NDCTL_EXPORT int ndctl_dimm_wait_overwrite(struct ndctl_dimm *dimm)
 			break;
 		}
 
-		if (strcmp(buf, "overwrite") == 0) {
+		if (strncmp(buf, "overwrite", 9) == 0) {
 			rc = poll(&fds, 1, -1);
 			if (rc < 0) {
 				rc = -errno;
@@ -839,7 +839,7 @@ NDCTL_EXPORT int ndctl_dimm_wait_overwrite(struct ndctl_dimm *dimm)
 			}
 			fds.revents = 0;
 		} else {
-			if (strcmp(buf, "disabled") == 0)
+			if (strncmp(buf, "disabled", 8) == 0)
 				rc = 1;
 			break;
 		}
-- 
2.20.1

_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [ndctl PATCH] libndctl: Fix a potentially non NUL-terminated string operation
  2019-09-20 18:06 [ndctl PATCH] libndctl: Fix a potentially non NUL-terminated string operation Vishal Verma
@ 2019-09-20 18:14 ` Dave Jiang
  0 siblings, 0 replies; 2+ messages in thread
From: Dave Jiang @ 2019-09-20 18:14 UTC (permalink / raw)
  To: Vishal Verma, linux-nvdimm



On 9/20/19 11:06 AM, Vishal Verma wrote:
> Static analysis warns that pread() doesn't NUL-terminate buffers, and
> that we shouldn't pass it directly to strcmp. The sysfs string should
> normally have the right termination, but for correctness in the library,
> we shouldn't rely on that. Replace the strcmp() calls in question with
> an explicit strncmp().
> 
> Fixes: 3c0c7db045ec ("ndctl: add a wait-overwrite command")
> Cc: Dave Jiang <dave.jiang@intel.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  ndctl/lib/dimm.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/ndctl/lib/dimm.c b/ndctl/lib/dimm.c
> index 2f145be..17344f0 100644
> --- a/ndctl/lib/dimm.c
> +++ b/ndctl/lib/dimm.c
> @@ -825,7 +825,7 @@ NDCTL_EXPORT int ndctl_dimm_wait_overwrite(struct ndctl_dimm *dimm)
>  			break;
>  		}
>  
> -		if (strcmp(buf, "overwrite") == 0) {
> +		if (strncmp(buf, "overwrite", 9) == 0) {
>  			rc = poll(&fds, 1, -1);
>  			if (rc < 0) {
>  				rc = -errno;
> @@ -839,7 +839,7 @@ NDCTL_EXPORT int ndctl_dimm_wait_overwrite(struct ndctl_dimm *dimm)
>  			}
>  			fds.revents = 0;
>  		} else {
> -			if (strcmp(buf, "disabled") == 0)
> +			if (strncmp(buf, "disabled", 8) == 0)
>  				rc = 1;
>  			break;
>  		}
> 
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, back to index

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-20 18:06 [ndctl PATCH] libndctl: Fix a potentially non NUL-terminated string operation Vishal Verma
2019-09-20 18:14 ` Dave Jiang

Linux-NVDIMM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-nvdimm/0 linux-nvdimm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-nvdimm linux-nvdimm/ https://lore.kernel.org/linux-nvdimm \
		linux-nvdimm@lists.01.org
	public-inbox-index linux-nvdimm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.01.lists.linux-nvdimm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git