diff mbox series

[net-next,6/9] i40e: use scnprintf over strncpy+strncat

Message ID 20231017190411.2199743-7-jacob.e.keller@intel.com (mailing list archive)
State Accepted
Commit be39d0a61aedafc6e7ec401d93fc7c477779996c
Delegated to: Netdev Maintainers
Headers show
Series Intel Wired LAN Driver Updates 2023-10-17 | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
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: 1363 this patch: 1363
netdev/cc_maintainers warning 5 maintainers not CCed: intel-wired-lan@lists.osuosl.org pabeni@redhat.com edumazet@google.com jesse.brandeburg@intel.com anthony.l.nguyen@intel.com
netdev/build_clang success Errors and warnings before: 1388 this patch: 1388
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: 1388 this patch: 1388
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 13 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Jacob Keller Oct. 17, 2023, 7:04 p.m. UTC 
From: Justin Stitt <justinstitt@google.com>

`strncpy` is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

Moreover, `strncat` shouldn't really be used either as per
fortify-string.h:
 * Do not use this function. While FORTIFY_SOURCE tries to avoid
 * read and write overflows, this is only possible when the sizes
 * of @p and @q are known to the compiler. Prefer building the
 * string with formatting, via scnprintf() or similar.

Instead, use `scnprintf` with "%s%s" format string. This code is now
more readable and robust.

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
Signed-off-by: Justin Stitt <justinstitt@google.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_ddp.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/i40e/i40e_ddp.c b/drivers/net/ethernet/intel/i40e/i40e_ddp.c
index 6b68b6575a1d..cf25bfc5dc3f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ddp.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ddp.c
@@ -456,10 +456,9 @@  int i40e_ddp_flash(struct net_device *netdev, struct ethtool_flash *flash)
 		char profile_name[sizeof(I40E_DDP_PROFILE_PATH)
 				  + I40E_DDP_PROFILE_NAME_MAX];
 
-		profile_name[sizeof(profile_name) - 1] = 0;
-		strncpy(profile_name, I40E_DDP_PROFILE_PATH,
-			sizeof(profile_name) - 1);
-		strncat(profile_name, flash->data, I40E_DDP_PROFILE_NAME_MAX);
+		scnprintf(profile_name, sizeof(profile_name), "%s%s",
+			  I40E_DDP_PROFILE_PATH, flash->data);
+
 		/* Load DDP recipe. */
 		status = request_firmware(&ddp_config, profile_name,
 					  &netdev->dev);