[PATCH v2 2/6] bna: ensure the copied buf is NUL terminated

[Bui Quang Minh <minhquangbui99@xxxxxxxxx>]

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

Fixes: 7afc5dbde091 ("bna: Add debugfs interface.")
Signed-off-by: Bui Quang Minh <minhquangbui99@xxxxxxxxx>
---
 drivers/net/ethernet/brocade/bna/bnad_debugfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/brocade/bna/bnad_debugfs.c b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c
index 7246e13dd559..97291bfbeea5 100644
--- a/drivers/net/ethernet/brocade/bna/bnad_debugfs.c
+++ b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c
@@ -312,7 +312,7 @@ bnad_debugfs_write_regrd(struct file *file, const char __user *buf,
 	void *kern_buf;
 
 	/* Copy the user space buf */
-	kern_buf = memdup_user(buf, nbytes);
+	kern_buf = memdup_user_nul(buf, nbytes);
 	if (IS_ERR(kern_buf))
 		return PTR_ERR(kern_buf);
 
@@ -372,7 +372,7 @@ bnad_debugfs_write_regwr(struct file *file, const char __user *buf,
 	void *kern_buf;
 
 	/* Copy the user space buf */
-	kern_buf = memdup_user(buf, nbytes);
+	kern_buf = memdup_user_nul(buf, nbytes);
 	if (IS_ERR(kern_buf))
 		return PTR_ERR(kern_buf);
 

-- 
2.34.1