[PATCH 320/437] drivers/net/brocade-bnad: ensure the copied buf is NULL terminated

Jens Axboe
2024-04-11T15:40:31Z

From: Bui Quang Minh <minhquangbui99@gmail.com>

Currently, we allocate a nbytes-sized kernel buffer and copy nbytes from
userspace to that buffer. Later, we use scanf on this buffer but we don't
ensure that the string is terminated inside the buffer, this can lead to
OOB read when using scanf. 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@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
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);

--
2.43.0