From: James Smart <jsmart2021@gmail.com>
Date: Fri, 1 Jul 2022 14:14:15 -0700
Subject: scsi: lpfc: Prevent buffer overflow crashes in debugfs with malformed
 user input
Patch-mainline: v5.20-rc1
Git-commit: f8191d40aa612981ce897e66cda6a88db8df17bb
References: bsc#1201956

Malformed user input to debugfs results in buffer overflow crashes.  Adapt
input string lengths to fit within internal buffers, leaving space for NULL
terminators.

Link: https://lore.kernel.org/r/20220701211425.2708-3-jsmart2021@gmail.com
Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/scsi/lpfc/lpfc_debugfs.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -2607,8 +2607,8 @@ lpfc_debugfs_multixripools_write(struct
 	struct lpfc_sli4_hdw_queue *qp;
 	struct lpfc_multixri_pool *multixri_pool;
 
-	if (nbytes > 64)
-		nbytes = 64;
+	if (nbytes > sizeof(mybuf) - 1)
+		nbytes = sizeof(mybuf) - 1;
 
 	memset(mybuf, 0, sizeof(mybuf));
 
@@ -2688,8 +2688,8 @@ lpfc_debugfs_nvmestat_write(struct file
 	if (!phba->targetport)
 		return -ENXIO;
 
-	if (nbytes > 64)
-		nbytes = 64;
+	if (nbytes > sizeof(mybuf) - 1)
+		nbytes = sizeof(mybuf) - 1;
 
 	memset(mybuf, 0, sizeof(mybuf));
 
@@ -2826,8 +2826,8 @@ lpfc_debugfs_ioktime_write(struct file *
 	char mybuf[64];
 	char *pbuf;
 
-	if (nbytes > 64)
-		nbytes = 64;
+	if (nbytes > sizeof(mybuf) - 1)
+		nbytes = sizeof(mybuf) - 1;
 
 	memset(mybuf, 0, sizeof(mybuf));
 
@@ -2954,8 +2954,8 @@ lpfc_debugfs_nvmeio_trc_write(struct fil
 	char mybuf[64];
 	char *pbuf;
 
-	if (nbytes > 63)
-		nbytes = 63;
+	if (nbytes > sizeof(mybuf) - 1)
+		nbytes = sizeof(mybuf) - 1;
 
 	memset(mybuf, 0, sizeof(mybuf));
 
@@ -3060,8 +3060,8 @@ lpfc_debugfs_hdwqstat_write(struct file
 	char *pbuf;
 	int i;
 
-	if (nbytes > 64)
-		nbytes = 64;
+	if (nbytes > sizeof(mybuf) - 1)
+		nbytes = sizeof(mybuf) - 1;
 
 	memset(mybuf, 0, sizeof(mybuf));