scsi: qedf: Ensure the copied buf is NUL terminated

jira VULN-43278
cve CVE-2024-38559
commit-author Bui Quang Minh <minhquangbui99@gmail.com>
commit d0184a3

Currently, we allocate a count-sized kernel buffer and copy count from
userspace to that buffer. Later, we use kstrtouint on this buffer but we
don't ensure that the string is terminated inside the buffer, this can
lead to OOB read when using kstrtouint. Fix this issue by using
memdup_user_nul instead of memdup_user.

Fixes: 61d8658 ("scsi: qedf: Add QLogic FastLinQ offload FCoE driver framework.")
	Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-4-f1f1b53a10f4@gmail.com
	Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit d0184a3)
	Signed-off-by: CIQ Kernel Automation <ciq_kernel_automation@ciq.com>

Author: CIQ Kernel Automation

drivers/scsi/qedf/qedf_debugfs.c

@@ -162,7 +162,7 @@ qedf_dbg_debug_cmd_write(struct file *filp, const char __user *buffer,
 	if (!count || *ppos)
 		return 0;
 
-	kern_buf = memdup_user(buffer, count);
+	kern_buf = memdup_user_nul(buffer, count);
 	if (IS_ERR(kern_buf))
 		return PTR_ERR(kern_buf);