[PATCH v2 3/6] bfa: ensure the copied buf is NUL terminated

Bui Quang Minh
2024-04-24T14:45:09Z

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: 9f30b674759b ("bfa: replace 2 kzalloc/copy_from_user by memdup_user")
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
---
drivers/scsi/bfa/bfad_debugfs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/bfa/bfad_debugfs.c b/drivers/scsi/bfa/bfad_debugfs.c
index 52db147d9979..f6dd077d47c9 100644
--- a/drivers/scsi/bfa/bfad_debugfs.c
+++ b/drivers/scsi/bfa/bfad_debugfs.c
@@ -250,7 +250,7 @@ bfad_debugfs_write_regrd(struct file *file, const char __user *buf,
unsigned long flags;
void *kern_buf;

- kern_buf = memdup_user(buf, nbytes);
+ kern_buf = memdup_user_nul(buf, nbytes);
if (IS_ERR(kern_buf))
return PTR_ERR(kern_buf);

@@ -317,7 +317,7 @@ bfad_debugfs_write_regwr(struct file *file, const char __user *buf,
unsigned long flags;
void *kern_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