The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
Thanks,
Sasha
------------------ original commit in Linus's tree ------------------
>From d10c77873ba1e9e6b91905018e29e196fd5f863d Mon Sep 17 00:00:00 2001
From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Date: Wed, 20 Dec 2023 15:52:11 +0900
Subject: [PATCH] ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()
If ->NameOffset/Length is bigger than ->CreateContextsOffset/Length,
ksmbd_check_message doesn't validate request buffer it correctly.
So slab-out-of-bounds warning from calling smb_strndup_from_utf16()
in smb2_open() could happen. If ->NameLength is non-zero, Set the larger
of the two sums (Name and CreateContext size) as the offset and length of
the data area.
Reported-by: Yang Chaoming <lometsj@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/smb/server/smb2misc.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/fs/smb/server/smb2misc.c b/fs/smb/server/smb2misc.c
index 23bd3d1209dfa..03dded29a9804 100644
--- a/fs/smb/server/smb2misc.c
+++ b/fs/smb/server/smb2misc.c
@@ -106,16 +106,25 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
break;
case SMB2_CREATE:
{
+ unsigned short int name_off =
+ le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset);
+ unsigned short int name_len =
+ le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength);
+
if (((struct smb2_create_req *)hdr)->CreateContextsLength) {
*off = le32_to_cpu(((struct smb2_create_req *)
hdr)->CreateContextsOffset);
*len = le32_to_cpu(((struct smb2_create_req *)
hdr)->CreateContextsLength);
- break;
+ if (!name_len)
+ break;
+
+ if (name_off + name_len < (u64)*off + *len)
+ break;
}
- *off = le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset);
- *len = le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength);
+ *off = name_off;
+ *len = name_len;
break;
}
case SMB2_QUERY_INFO:
--
2.43.0
