scsi: 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 <minhquangbui99@gmail.com>
Link: https://lore.kernel.org/r/20240424-fix-oob-read-v2-3-f1f1b53a10f4@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/bfa/bfad_debugfs.c b/drivers/scsi/bfa/bfad_debugfs.c
index 52db147d9979da9e49d10bc28904dd928ff08979..f6dd077d47c9a7e0a65f67b05946cfe7163948c4 100644 (file)
--- 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);