ksmbd: validate the zero field of packet header

[ Upstream commit 516b3eb8c8 ]

The SMB2 Protocol requires that "The first byte of the Direct TCP
transport packet header MUST be zero (0x00)"[1]. Commit 1c1bcf2d3e
("ksmbd: validate smb request protocol id") removed the validation of
this 1-byte zero. Add the validation back now.

[1]: [MS-SMB2] - v20230227, page 30.
https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-SMB2/%5bMS-SMB2%5d-230227.pdf

Fixes: 1c1bcf2d3e ("ksmbd: validate smb request protocol id")
Signed-off-by: Li Nan <linan122@huawei.com>
Acked-by: Tom Talpey <tom@talpey.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Li Nan 2023-12-08 14:56:47 +08:00 • committed by Greg Kroah-Hartman
commit 36fdccf845