accel/habanalabs: refactor deprecated strncpy to strscpy_pad

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

We see that `prop->cpucp_info.card_name` is supposed to be
NUL-terminated based on its usage within `__hwmon_device_register()`
(wherein it's called "name"):
|	if (name && (!strlen(name) || strpbrk(name, "-* \t\n")))
|		dev_warn(dev,
|			 "hwmon: '%s' is not a valid name attribute, please fix\n",
|			 name);

A suitable replacement is `strscpy_pad` [2] due to the fact that it
guarantees both NUL-termination and NUL-padding on its destination
buffer.

NUL-padding on `prop->cpucp_info.card_name` is not strictly necessary as
`hdev->prop` is explicitly zero-initialized but should be used
regardless as it gets copied out to userspace directly -- as per Kees'
suggestion.

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>
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

3 files changed, 7 insertions, 6 deletions

diff --git a/drivers/accel/habanalabs/gaudi/gaudi.c b/drivers/accel/habanalabs/gaudi/gaudi.c
index e0f6541eb3d6..29fb71c8b47f 100644
--- a/drivers/accel/habanalabs/gaudi/gaudi.c
+++ b/drivers/accel/habanalabs/gaudi/gaudi.c
@@ -664,7 +664,7 @@ static int gaudi_set_fixed_properties(struct hl_device *hdev)
 	prop->pcie_dbi_base_address = mmPCIE_DBI_BASE;
 	prop->pcie_aux_dbi_reg_addr = CFG_BASE + mmPCIE_AUX_DBI;
 
-	strncpy(prop->cpucp_info.card_name, GAUDI_DEFAULT_CARD_NAME,
+	strscpy_pad(prop->cpucp_info.card_name, GAUDI_DEFAULT_CARD_NAME,
 					CARD_NAME_MAX_LEN);
 
 	prop->max_pending_cs = GAUDI_MAX_PENDING_CS;
@@ -8004,7 +8004,7 @@ static int gaudi_cpucp_info_get(struct hl_device *hdev)
 		return rc;
 
 	if (!strlen(prop->cpucp_info.card_name))
-		strncpy(prop->cpucp_info.card_name, GAUDI_DEFAULT_CARD_NAME,
+		strscpy_pad(prop->cpucp_info.card_name, GAUDI_DEFAULT_CARD_NAME,
 				CARD_NAME_MAX_LEN);
 
 	hdev->card_type = le32_to_cpu(hdev->asic_prop.cpucp_info.card_type);
diff --git a/drivers/accel/habanalabs/gaudi2/gaudi2.c b/drivers/accel/habanalabs/gaudi2/gaudi2.c
index d94acec63d95..e53de95b1791 100644
--- a/drivers/accel/habanalabs/gaudi2/gaudi2.c
+++ b/drivers/accel/habanalabs/gaudi2/gaudi2.c
@@ -2528,7 +2528,7 @@ static int gaudi2_set_fixed_properties(struct hl_device *hdev)
 	prop->pcie_dbi_base_address = CFG_BASE + mmPCIE_DBI_BASE;
 	prop->pcie_aux_dbi_reg_addr = CFG_BASE + mmPCIE_AUX_DBI;
 
-	strncpy(prop->cpucp_info.card_name, GAUDI2_DEFAULT_CARD_NAME, CARD_NAME_MAX_LEN);
+	strscpy_pad(prop->cpucp_info.card_name, GAUDI2_DEFAULT_CARD_NAME, CARD_NAME_MAX_LEN);
 
 	prop->mme_master_slave_mode = 1;
 
@@ -2981,7 +2981,8 @@ static int gaudi2_cpucp_info_get(struct hl_device *hdev)
 	}
 
 	if (!strlen(prop->cpucp_info.card_name))
-		strncpy(prop->cpucp_info.card_name, GAUDI2_DEFAULT_CARD_NAME, CARD_NAME_MAX_LEN);
+		strscpy_pad(prop->cpucp_info.card_name, GAUDI2_DEFAULT_CARD_NAME,
+				CARD_NAME_MAX_LEN);
 
 	/* Overwrite binning masks with the actual binning values from F/W */
 	hdev->dram_binning = prop->cpucp_info.dram_binning_mask;
diff --git a/drivers/accel/habanalabs/goya/goya.c b/drivers/accel/habanalabs/goya/goya.c
index 7c685e6075f6..024ccf2e159b 100644
--- a/drivers/accel/habanalabs/goya/goya.c
+++ b/drivers/accel/habanalabs/goya/goya.c
@@ -466,7 +466,7 @@ int goya_set_fixed_properties(struct hl_device *hdev)
 	prop->pcie_dbi_base_address = mmPCIE_DBI_BASE;
 	prop->pcie_aux_dbi_reg_addr = CFG_BASE + mmPCIE_AUX_DBI;
 
-	strncpy(prop->cpucp_info.card_name, GOYA_DEFAULT_CARD_NAME,
+	strscpy_pad(prop->cpucp_info.card_name, GOYA_DEFAULT_CARD_NAME,
 		CARD_NAME_MAX_LEN);
 
 	prop->max_pending_cs = GOYA_MAX_PENDING_CS;
@@ -5122,7 +5122,7 @@ int goya_cpucp_info_get(struct hl_device *hdev)
 	}
 
 	if (!strlen(prop->cpucp_info.card_name))
-		strncpy(prop->cpucp_info.card_name, GOYA_DEFAULT_CARD_NAME,
+		strscpy_pad(prop->cpucp_info.card_name, GOYA_DEFAULT_CARD_NAME,
 				CARD_NAME_MAX_LEN);
 
 	return 0;