From: Thorsten Blum <thorsten.blum@linux.dev>
Date: Fri, 5 Sep 2025 10:31:45 +0000 (+0200)
Subject: scsi: scsi_debug: Replace kzalloc() + copy_from_user() with memdup_user_nul()
X-Git-Tag: v6.18-rc1~100^2~21
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8791b07894ab75361195094828dc56b7ed449c36;p=thirdparty%2Fkernel%2Fstable.git

scsi: scsi_debug: Replace kzalloc() + copy_from_user() with memdup_user_nul()

Replace kzalloc() followed by copy_from_user() with memdup_user_nul() to
improve and simplify sdebug_error_write().

No functional changes intended.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 90943857243c1..2a8638937d239 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -1155,14 +1155,9 @@ static ssize_t sdebug_error_write(struct file *file, const char __user *ubuf,
 	struct sdebug_err_inject *inject;
 	struct scsi_device *sdev = (struct scsi_device *)file->f_inode->i_private;
 
-	buf = kzalloc(count + 1, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	if (copy_from_user(buf, ubuf, count)) {
-		kfree(buf);
-		return -EFAULT;
-	}
+	buf = memdup_user_nul(ubuf, count);
+	if (IS_ERR(buf))
+		return PTR_ERR(buf);
 
 	if (buf[0] == '-')
 		return sdebug_err_remove(sdev, buf, count);