diff mbox series

[v3] net: dsa: lan9303: use ethtool_puts() for lan9303_get_strings()

Message ID 20240408-strncpy-drivers-net-dsa-lan9303-core-c-v3-1-0c313694d25b@google.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series [v3] net: dsa: lan9303: use ethtool_puts() for lan9303_get_strings() | expand

Checks

Context Check Description
netdev/series_format warning Single patches do not need cover letters; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 942 this patch: 942
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 953 this patch: 953
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 953 this patch: 953
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-04-09--03-00 (tests: 952)

Commit Message

Justin Stitt April 8, 2024, 9:01 p.m. UTC
This pattern of strncpy with some pointer arithmetic setting fixed-sized
intervals with string literal data is a bit weird so let's use
ethtool_puts() as this has more obvious behavior and is less-error
prone.

Nicely, we also get to drop a usage of the now deprecated strncpy() [1].

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
Changes in v3:
- use ethtool_puts over ethtool_sprintf
- Link to v2: https://lore.kernel.org/r/20231005-strncpy-drivers-net-dsa-lan9303-core-c-v2-1-feb452a532db@google.com

Changes in v2:
- use ethtool_sprintf (thanks Alexander)
- Link to v1: https://lore.kernel.org/r/20231005-strncpy-drivers-net-dsa-lan9303-core-c-v1-1-5a66c538147e@google.com
---
 drivers/net/dsa/lan9303-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)


---
base-commit: c85af715cac0a951eea97393378e84bb49384734
change-id: 20231005-strncpy-drivers-net-dsa-lan9303-core-c-6386858e5c22

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

Comments

Kees Cook April 8, 2024, 11:20 p.m. UTC | #1
On Mon, Apr 08, 2024 at 09:01:57PM +0000, Justin Stitt wrote:
> This pattern of strncpy with some pointer arithmetic setting fixed-sized
> intervals with string literal data is a bit weird so let's use
> ethtool_puts() as this has more obvious behavior and is less-error
> prone.
> 
> Nicely, we also get to drop a usage of the now deprecated strncpy() [1].
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Cc: Kees Cook <keescook@chromium.org>
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Reviewed-by: Kees Cook <keescook@chromium.org>
Alexander Lobakin April 9, 2024, 8:58 a.m. UTC | #2
From: Justin Stitt <justinstitt@google.com>
Date: Mon, 08 Apr 2024 21:01:57 +0000

> This pattern of strncpy with some pointer arithmetic setting fixed-sized
> intervals with string literal data is a bit weird so let's use
> ethtool_puts() as this has more obvious behavior and is less-error
> prone.
> 
> Nicely, we also get to drop a usage of the now deprecated strncpy() [1].
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Cc: Kees Cook <keescook@chromium.org>
> Signed-off-by: Justin Stitt <justinstitt@google.com>
> Suggested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
> ---
> Changes in v3:
> - use ethtool_puts over ethtool_sprintf
> - Link to v2: https://lore.kernel.org/r/20231005-strncpy-drivers-net-dsa-lan9303-core-c-v2-1-feb452a532db@google.com
> 
> Changes in v2:
> - use ethtool_sprintf (thanks Alexander)
> - Link to v1: https://lore.kernel.org/r/20231005-strncpy-drivers-net-dsa-lan9303-core-c-v1-1-5a66c538147e@google.com
> ---
>  drivers/net/dsa/lan9303-core.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
> index fcb20eac332a..04d3af0eb28e 100644
> --- a/drivers/net/dsa/lan9303-core.c
> +++ b/drivers/net/dsa/lan9303-core.c
> @@ -1007,14 +1007,14 @@ static const struct lan9303_mib_desc lan9303_mib[] = {
>  static void lan9303_get_strings(struct dsa_switch *ds, int port,
>  				u32 stringset, uint8_t *data)
>  {
> +	u8 *buf = data;
>  	unsigned int u;
>  
>  	if (stringset != ETH_SS_STATS)
>  		return;
>  
>  	for (u = 0; u < ARRAY_SIZE(lan9303_mib); u++) {
> -		strncpy(data + u * ETH_GSTRING_LEN, lan9303_mib[u].name,
> -			ETH_GSTRING_LEN);
> +		ethtool_puts(&buf, lan9303_mib[u].name);
>  	}

The braces { } around ethtool_puts() aren't needed anymore.

>  }
>  
> 
> ---
> base-commit: c85af715cac0a951eea97393378e84bb49384734
> change-id: 20231005-strncpy-drivers-net-dsa-lan9303-core-c-6386858e5c22
> 
> Best regards,
> --
> Justin Stitt <justinstitt@google.com>

Thanks,
Olek
diff mbox series

Patch

diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c
index fcb20eac332a..04d3af0eb28e 100644
--- a/drivers/net/dsa/lan9303-core.c
+++ b/drivers/net/dsa/lan9303-core.c
@@ -1007,14 +1007,14 @@  static const struct lan9303_mib_desc lan9303_mib[] = {
 static void lan9303_get_strings(struct dsa_switch *ds, int port,
 				u32 stringset, uint8_t *data)
 {
+	u8 *buf = data;
 	unsigned int u;
 
 	if (stringset != ETH_SS_STATS)
 		return;
 
 	for (u = 0; u < ARRAY_SIZE(lan9303_mib); u++) {
-		strncpy(data + u * ETH_GSTRING_LEN, lan9303_mib[u].name,
-			ETH_GSTRING_LEN);
+		ethtool_puts(&buf, lan9303_mib[u].name);
 	}
 }