[PATCH AUTOSEL 3.18 6/6] ubifs: Check for name being NULL while mounting

[Sasha Levin <sashal@kernel.org>]

From: Richard Weinberger <richard@nod.at>

[ Upstream commit 37f31b6ca4311b94d985fb398a72e5399ad57925 ]

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: Sasha Levin <alexander.levin@microsoft.com>
---
 fs/ubifs/super.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 2f7a74e73b7d..a6a2108bf620 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1917,6 +1917,9 @@ 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))
-- 
2.17.1