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* [PATCH v2] aoe: replace strncpy with strscpy
@ 2023-09-19  5:27 Justin Stitt
  2023-09-20 15:36 ` Kees Cook
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Justin Stitt @ 2023-09-19  5:27 UTC (permalink / raw)
  To: Justin Sanders, Jens Axboe
  Cc: linux-block, linux-kernel, linux-hardening, Kees Cook, Xu Panda,
	Yang Yang, Justin Stitt

`strncpy` is deprecated for use on NUL-terminated destination strings [1].

`aoe_iflist` is expected to be NUL-terminated which is evident by its
use with string apis later on like `strspn`:
| 	p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);

It also seems `aoe_iflist` does not need to be NUL-padded which means
`strscpy` [2] is a suitable replacement due to the fact that it
guarantees NUL-termination on the destination buffer while not
unnecessarily NUL-padding.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Cc: Xu Panda <xu.panda@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com>
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Changes in v2:
- reword subject line (thanks Jens)
- rebase onto 3669558bdf35
- Link to v1: https://lore.kernel.org/r/20230911-strncpy-drivers-block-aoe-aoenet-c-v1-1-9643d6137ff9@google.com
---
Note: This exact same patch exists [3] but seemed to die so I'm
resending.

[3]: https://lore.kernel.org/all/202212051930256039214@zte.com.cn/
---
 drivers/block/aoe/aoenet.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/block/aoe/aoenet.c b/drivers/block/aoe/aoenet.c
index 63773a90581d..c51ea95bc2ce 100644
--- a/drivers/block/aoe/aoenet.c
+++ b/drivers/block/aoe/aoenet.c
@@ -39,8 +39,7 @@ static struct ktstate kts;
 #ifndef MODULE
 static int __init aoe_iflist_setup(char *str)
 {
-	strncpy(aoe_iflist, str, IFLISTSZ);
-	aoe_iflist[IFLISTSZ - 1] = '\0';
+	strscpy(aoe_iflist, str, IFLISTSZ);
 	return 1;
 }
 

---
base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec
change-id: 20230911-strncpy-drivers-block-aoe-aoenet-c-024debad6105

Best regards,
--
Justin Stitt <justinstitt@google.com>


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] aoe: replace strncpy with strscpy
  2023-09-19  5:27 [PATCH v2] aoe: replace strncpy with strscpy Justin Stitt
@ 2023-09-20 15:36 ` Kees Cook
  2023-10-03 23:58 ` Kees Cook
  2023-10-04  0:23 ` Jens Axboe
  2 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2023-09-20 15:36 UTC (permalink / raw)
  To: Justin Stitt
  Cc: Justin Sanders, Jens Axboe, linux-block, linux-kernel,
	linux-hardening, Xu Panda, Yang Yang

On Tue, Sep 19, 2023 at 05:27:45AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
> 
> `aoe_iflist` is expected to be NUL-terminated which is evident by its
> use with string apis later on like `strspn`:
> | 	p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
> 
> It also seems `aoe_iflist` does not need to be NUL-padded which means
> `strscpy` [2] is a suitable replacement due to the fact that it
> guarantees NUL-termination on the destination buffer while not
> unnecessarily NUL-padding.
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Xu Panda <xu.panda@zte.com.cn>
> Cc: Yang Yang <yang.yang29@zte.com>
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Looks right. Thanks!

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] aoe: replace strncpy with strscpy
  2023-09-19  5:27 [PATCH v2] aoe: replace strncpy with strscpy Justin Stitt
  2023-09-20 15:36 ` Kees Cook
@ 2023-10-03 23:58 ` Kees Cook
  2023-10-04  0:23 ` Jens Axboe
  2 siblings, 0 replies; 4+ messages in thread
From: Kees Cook @ 2023-10-03 23:58 UTC (permalink / raw)
  To: Jens Axboe
  Cc: Justin Sanders, Justin Stitt, linux-block, linux-kernel,
	linux-hardening, Xu Panda, Yang Yang

On Tue, Sep 19, 2023 at 05:27:45AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
> 
> `aoe_iflist` is expected to be NUL-terminated which is evident by its
> use with string apis later on like `strspn`:
> | 	p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
> 
> It also seems `aoe_iflist` does not need to be NUL-padded which means
> `strscpy` [2] is a suitable replacement due to the fact that it
> guarantees NUL-termination on the destination buffer while not
> unnecessarily NUL-padding.
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Xu Panda <xu.panda@zte.com.cn>
> Cc: Yang Yang <yang.yang29@zte.com>
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Friendly ping on this patch. Jens, do you want to pick this up?

-- 
Kees Cook

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] aoe: replace strncpy with strscpy
  2023-09-19  5:27 [PATCH v2] aoe: replace strncpy with strscpy Justin Stitt
  2023-09-20 15:36 ` Kees Cook
  2023-10-03 23:58 ` Kees Cook
@ 2023-10-04  0:23 ` Jens Axboe
  2 siblings, 0 replies; 4+ messages in thread
From: Jens Axboe @ 2023-10-04  0:23 UTC (permalink / raw)
  To: Justin Sanders, Justin Stitt
  Cc: linux-block, linux-kernel, linux-hardening, Kees Cook, Xu Panda,
	Yang Yang


On Tue, 19 Sep 2023 05:27:45 +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
> 
> `aoe_iflist` is expected to be NUL-terminated which is evident by its
> use with string apis later on like `strspn`:
> | 	p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
> 
> It also seems `aoe_iflist` does not need to be NUL-padded which means
> `strscpy` [2] is a suitable replacement due to the fact that it
> guarantees NUL-termination on the destination buffer while not
> unnecessarily NUL-padding.
> 
> [...]

Applied, thanks!

[1/1] aoe: replace strncpy with strscpy
      commit: 5e9b7cfc209b84d135993b8cb75ea383f24b2bba

Best regards,
-- 
Jens Axboe




^ permalink raw reply	[flat|nested] 4+ messages in thread

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2023-09-19  5:27 [PATCH v2] aoe: replace strncpy with strscpy Justin Stitt
2023-09-20 15:36 ` Kees Cook
2023-10-03 23:58 ` Kees Cook
2023-10-04  0:23 ` Jens Axboe

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