From: Namjae Jeon <linkinjeon@xxxxxxxxxx>
[ Upstream commit a80a486d72e20bd12c335bcd38b6e6f19356b0aa ]
If ->NameOffset of smb2_create_req is smaller than Buffer offset of
smb2_create_req, slab-out-of-bounds read can happen from smb2_open.
This patch set the minimum value of the name offset to the buffer offset
to validate name length of smb2_create_req().
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Xuanzhe Yu <yuxuanzhe@xxxxxxxxxxx>
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Stable-dep-of: c6cd2e8d2d9a ("ksmbd: fix potencial out-of-bounds when buffer offset is invalid")
Signed-off-by: Vamsi Krishna Brahmajosyula <vamsi-krishna.brahmajosyula@xxxxxxxxxxxx>
---
fs/smb/server/smb2misc.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/smb/server/smb2misc.c b/fs/smb/server/smb2misc.c
index 03dded29a980..7c872ffb4b0a 100644
--- a/fs/smb/server/smb2misc.c
+++ b/fs/smb/server/smb2misc.c
@@ -107,7 +107,10 @@ static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
case SMB2_CREATE:
{
unsigned short int name_off =
- le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset);
+ max_t(unsigned short int,
+ le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset),
+ offsetof(struct smb2_create_req, Buffer));
+
unsigned short int name_len =
le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength);
--
2.39.4
