ksmbd: fix potencial out-of-bounds when buffer offset is invalid

I found potencial out-of-bounds when buffer offset fields of a few requests
is invalid. This patch set the minimum value of buffer offset field to
->Buffer offset to validate buffer length.

Cc: stable@vger.kernel.org
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: fix slab-out-of-bounds in smb_strndup_from_utf16()

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@vger.kernel.org
Reported-by: Xuanzhe Yu <yuxuanzhe@outlook.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

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@live.com>
Cc: stable@vger.kernel.org
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: return invalid parameter error response if smb2 request is invalid

If smb2 request from client is invalid, The following kernel oops could
happen. The patch e2b76ab8b5c9: "ksmbd: add support for read compound"
leads this issue. When request is invalid, It doesn't set anything in
the response buffer. This patch add missing set invalid parameter error
response.

[ 673.085542] ksmbd: cli req too short, len 184 not 142. cmd:5 mid:109
[ 673.085580] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 673.085591] #PF: supervisor read access in kernel mode
[ 673.085600] #PF: error_code(0x0000) - not-present page
[ 673.085608] PGD 0 P4D 0
[ 673.085620] Oops: 0000 [#1] PREEMPT SMP NOPTI
[ 673.085631] CPU: 3 PID: 1039 Comm: kworker/3:0 Not tainted 6.6.0-rc2-tmt #16
[ 673.085643] Hardware name: AZW U59/U59, BIOS JTKT001 05/05/2022
[ 673.085651] Workqueue: ksmbd-io handle_ksmbd_work [ksmbd]
[ 673.085719] RIP: 0010:ksmbd_conn_write+0x68/0xc0 [ksmbd]
[ 673.085808] RAX: 0000000000000000 RBX: ffff88811ade4f00 RCX: 0000000000000000
[ 673.085817] RDX: 0000000000000000 RSI: ffff88810c2a9780 RDI: ffff88810c2a9ac0
[ 673.085826] RBP: ffffc900005e3e00 R08: 0000000000000000 R09: 0000000000000000
[ 673.085834] R10: ffffffffa3168160 R11: 63203a64626d736b R12: ffff8881057c8800
[ 673.085842] R13: ffff8881057c8820 R14: ffff8882781b2380 R15: ffff8881057c8800
[ 673.085852] FS: 0000000000000000(0000) GS:ffff888278180000(0000) knlGS:0000000000000000
[ 673.085864] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 673.085872] CR2: 0000000000000000 CR3: 000000015b63c000 CR4: 0000000000350ee0
[ 673.085883] Call Trace:
[ 673.085890] <TASK>
[ 673.085900] ? show_regs+0x6a/0x80
[ 673.085916] ? __die+0x25/0x70
[ 673.085926] ? page_fault_oops+0x154/0x4b0
[ 673.085938] ? tick_nohz_tick_stopped+0x18/0x50
[ 673.085954] ? __irq_work_queue_local+0xba/0x140
[ 673.085967] ? do_user_addr_fault+0x30f/0x6c0
[ 673.085979] ? exc_page_fault+0x79/0x180
[ 673.085992] ? asm_exc_page_fault+0x27/0x30
[ 673.086009] ? ksmbd_conn_write+0x68/0xc0 [ksmbd]
[ 673.086067] ? ksmbd_conn_write+0x46/0xc0 [ksmbd]
[ 673.086123] handle_ksmbd_work+0x28d/0x4b0 [ksmbd]
[ 673.086177] process_one_work+0x178/0x350
[ 673.086193] ? __pfx_worker_thread+0x10/0x10
[ 673.086202] worker_thread+0x2f3/0x420
[ 673.086210] ? _raw_spin_unlock_irqrestore+0x27/0x50
[ 673.086222] ? __pfx_worker_thread+0x10/0x10
[ 673.086230] kthread+0x103/0x140
[ 673.086242] ? __pfx_kthread+0x10/0x10
[ 673.086253] ret_from_fork+0x39/0x60
[ 673.086263] ? __pfx_kthread+0x10/0x10
[ 673.086274] ret_from_fork_asm+0x1b/0x30

Fixes: e2b76ab8b5c9 ("ksmbd: add support for read compound")
Reported-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: validate command request size

In commit 2b9b8f3b68ed ("ksmbd: validate command payload size"), except
for SMB2_OPLOCK_BREAK_HE command, the request size of other commands
is not checked, it's not expected. Fix it by add check for request
size of other commands.

Cc: stable@vger.kernel.org
Fixes: 2b9b8f3b68ed ("ksmbd: validate command payload size")
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Long Li <leo.lilong@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: fix out-of-bound read in smb2_write

ksmbd_smb2_check_message doesn't validate hdr->NextCommand. If
->NextCommand is bigger than Offset + Length of smb2 write, It will
allow oversized smb2 write length. It will cause OOB read in smb2_write.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21164
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: validate command payload size

->StructureSize2 indicates command payload size. ksmbd should validate
this size with rfc1002 length before accessing it.
This patch remove unneeded check and add the validation for this.

[ 8.912583] BUG: KASAN: slab-out-of-bounds in ksmbd_smb2_check_message+0x12a/0xc50
[ 8.913051] Read of size 2 at addr ffff88800ac7d92c by task kworker/0:0/7
...
[ 8.914967] Call Trace:
[ 8.915126] <TASK>
[ 8.915267] dump_stack_lvl+0x33/0x50
[ 8.915506] print_report+0xcc/0x620
[ 8.916558] kasan_report+0xae/0xe0
[ 8.917080] kasan_check_range+0x35/0x1b0
[ 8.917334] ksmbd_smb2_check_message+0x12a/0xc50
[ 8.917935] ksmbd_verify_smb_message+0xae/0xd0
[ 8.918223] handle_ksmbd_work+0x192/0x820
[ 8.918478] process_one_work+0x419/0x760
[ 8.918727] worker_thread+0x2a2/0x6f0
[ 8.919222] kthread+0x187/0x1d0
[ 8.919723] ret_from_fork+0x1f/0x30
[ 8.919954] </TASK>

Cc: stable@vger.kernel.org
Reported-by: Chih-Yen Chang <cc85nod@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

smb: move client and server files to common directory fs/smb

Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko
and helper modules) to new fs/smb subdirectory:

fs/cifs --> fs/smb/client
fs/ksmbd --> fs/smb/server
fs/smbfs_common --> fs/smb/common

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>