2024-04-24 14:46:10

by Bui Quang Minh

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

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 <[email protected]>
---
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

2024-05-07 01:20:35

by Martin K. Petersen

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

Bui,

> 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.

Applied to 6.10/scsi-staging, thanks!

--
Martin K. Petersen Oracle Linux Engineering