ubifs: Check for name being NULL while mounting

commit 37f31b6ca4311b94d985fb398a72e5399ad57925 upstream.

The requested device name can be NULL or an empty string.
Check for that and refuse to continue. UBIFS has to do this manually
since we cannot use mount_bdev(), which checks for this condition.

Fixes: 1e51764a3c2ac ("UBIFS: add new flash file system")
Reported-by: syzbot+38bd0f7865e5c6379280@syzkaller.appspotmail.com
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 03dda1cbe485a9f8eae3ed04d57cf635eac3e7dd..727a9e3fa806fd6ed6ea9d1799c307cf4acd7ed5 100644 (file)
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1918,6 +1918,9 @@ static struct ubi_volume_desc *open_ubi(const char *name, int mode)
        int dev, vol;
        char *endptr;
 
+       if (!name || !*name)
+               return ERR_PTR(-EINVAL);
+
        /* First, try to open using the device node path method */
        ubi = ubi_open_volume_path(name, mode);
        if (!IS_ERR(ubi))