[PATCH v2] scsi: elx: sli4: Replace deprecated strncpy() with strscpy()

[PATCH v2] scsi: elx: sli4: Replace deprecated strncpy() with strscpy()

[Thorsten Blum]

strncpy() is deprecated for NUL-terminated destination buffers; use
strscpy() instead.

Since sli_config_cmd_init() already zeroes out the destination buffers,
the potential NUL-padding by strncpy() is unnecessary. strscpy() copies
only the required characters and guarantees NUL-termination.

And since all three destination buffers have a fixed length, strscpy()
automatically determines their size using sizeof() when the argument is
omitted. This makes any explicit sizeof() calls unnecessary.

The source strings are also NUL-terminated and meet the __must_be_cstr()
requirement of strscpy().

No functional changes intended.

Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
Changes in v2:
- Update patch description as suggested by Kees
- Link to v1: https://lore.kernel.org/lkml/20250226185531.1092-2-thorsten.blum@linux.dev/
---
 drivers/scsi/elx/libefc_sli/sli4.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/elx/libefc_sli/sli4.c b/drivers/scsi/elx/libefc_sli/sli4.c
index 5e7fb110bc3f..d9a231fc0e0d 100644
--- a/drivers/scsi/elx/libefc_sli/sli4.c
+++ b/drivers/scsi/elx/libefc_sli/sli4.c
@@ -3804,7 +3804,7 @@ sli_cmd_common_write_object(struct sli4 *sli4, void *buf, u16 noc,
 	wr_obj->desired_write_len_dword = cpu_to_le32(dwflags);
 
 	wr_obj->write_offset = cpu_to_le32(offset);
-	strncpy(wr_obj->object_name, obj_name, sizeof(wr_obj->object_name) - 1);
+	strscpy(wr_obj->object_name, obj_name);
 	wr_obj->host_buffer_descriptor_count = cpu_to_le32(1);
 
 	bde = (struct sli4_bde *)wr_obj->host_buffer_descriptor;
@@ -3833,7 +3833,7 @@ sli_cmd_common_delete_object(struct sli4 *sli4, void *buf, char *obj_name)
 			 SLI4_SUBSYSTEM_COMMON, CMD_V0,
 			 SLI4_RQST_PYLD_LEN(cmn_delete_object));
 
-	strncpy(req->object_name, obj_name, sizeof(req->object_name) - 1);
+	strscpy(req->object_name, obj_name);
 	return 0;
 }
 
@@ -3856,7 +3856,7 @@ sli_cmd_common_read_object(struct sli4 *sli4, void *buf, u32 desired_read_len,
 		cpu_to_le32(desired_read_len & SLI4_REQ_DESIRE_READLEN);
 
 	rd_obj->read_offset = cpu_to_le32(offset);
-	strncpy(rd_obj->object_name, obj_name, sizeof(rd_obj->object_name) - 1);
+	strscpy(rd_obj->object_name, obj_name);
 	rd_obj->host_buffer_descriptor_count = cpu_to_le32(1);
 
 	bde = (struct sli4_bde *)rd_obj->host_buffer_descriptor;
-- 
2.49.0

Re: [PATCH v2] scsi: elx: sli4: Replace deprecated strncpy() with strscpy()

[Kees Cook]

On Tue, Apr 08, 2025 at 12:28:40PM +0200, Thorsten Blum wrote:
> strncpy() is deprecated for NUL-terminated destination buffers; use
> strscpy() instead.
> 
> Since sli_config_cmd_init() already zeroes out the destination buffers,
> the potential NUL-padding by strncpy() is unnecessary. strscpy() copies
> only the required characters and guarantees NUL-termination.
> 
> And since all three destination buffers have a fixed length, strscpy()
> automatically determines their size using sizeof() when the argument is
> omitted. This makes any explicit sizeof() calls unnecessary.
> 
> The source strings are also NUL-terminated and meet the __must_be_cstr()
> requirement of strscpy().
> 
> No functional changes intended.
> 
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>

Reviewed-by: Kees Cook <kees@kernel.org>

-- 
Kees Cook

Re: [PATCH v2] scsi: elx: sli4: Replace deprecated strncpy() with strscpy()

[Martin K. Petersen]

Thorsten,

> strncpy() is deprecated for NUL-terminated destination buffers; use
> strscpy() instead.

Applied to 6.16/scsi-staging, thanks!

-- 
Martin K. Petersen