[PATCH AUTOSEL 4.19 01/22] scsi: lpfc: Fix possible file string name overflow when updating firmware

[Sasha Levin <sashal@kernel.org>]

From: Justin Tee <justin.tee@broadcom.com>

[ Upstream commit f5779b529240b715f0e358489ad0ed933bf77c97 ]

Because file_name and phba->ModelName are both declared a size 80 bytes,
the extra ".grp" file extension could cause an overflow into file_name.

Define a ELX_FW_NAME_SIZE macro with value 84.  84 incorporates the 4 extra
characters from ".grp".  file_name is changed to be declared as a char and
initialized to zeros i.e. null chars.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20231031191224.150862-3-justintee8345@gmail.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/lpfc/lpfc.h      | 1 +
 drivers/scsi/lpfc/lpfc_init.c | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
index 706aca3f7c25..53b661793268 100644
--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -32,6 +32,7 @@
 struct lpfc_sli2_slim;
 
 #define ELX_MODEL_NAME_SIZE	80
+#define ELX_FW_NAME_SIZE	84
 
 #define LPFC_PCI_DEV_LP		0x1
 #define LPFC_PCI_DEV_OC		0x2
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index c6caacaa3e7a..7db4e893e10e 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -11428,7 +11428,7 @@ lpfc_write_firmware(const struct firmware *fw, void *context)
 int
 lpfc_sli4_request_firmware_update(struct lpfc_hba *phba, uint8_t fw_upgrade)
 {
-	uint8_t file_name[ELX_MODEL_NAME_SIZE];
+	char file_name[ELX_FW_NAME_SIZE] = {0};
 	int ret;
 	const struct firmware *fw;
 
@@ -11437,7 +11437,7 @@ lpfc_sli4_request_firmware_update(struct lpfc_hba *phba, uint8_t fw_upgrade)
 	    LPFC_SLI_INTF_IF_TYPE_2)
 		return -EPERM;
 
-	snprintf(file_name, ELX_MODEL_NAME_SIZE, "%s.grp", phba->ModelName);
+	scnprintf(file_name, sizeof(file_name), "%s.grp", phba->ModelName);
 
 	if (fw_upgrade == INT_FW_UPGRADE) {
 		ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_HOTPLUG,
-- 
2.43.0