ksmbd: replace generic_fillattr with vfs_getattr

generic_fillattr should not be used outside of ->getattr
implementations.

Use vfs_getattr instead, and adapt functions to return an
error code to the caller.

Cc: stable@vger.kernel.org
Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: validate the zero field of packet header

The SMB2 Protocol requires that "The first byte of the Direct TCP
transport packet header MUST be zero (0x00)"[1]. Commit 1c1bcf2d3ea0
("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: 1c1bcf2d3ea0 ("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>

ksmbd: handle malformed smb1 message

If set_smb1_rsp_status() is not implemented, It will cause NULL pointer
dereferece error when client send malformed smb1 message.
This patch add set_smb1_rsp_status() to ignore malformed smb1 message.

Cc: stable@vger.kernel.org
Reported-by: Robert Morris <rtm@csail.mit.edu>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: add support for read compound

MacOS sends a compound request including read to the server
(e.g. open-read-close). So far, ksmbd has not handled read as
a compound request. For compatibility between ksmbd and an OS that
supports SMB, This patch provides compound support for read requests.

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

ksmbd: fix out of bounds in init_smb2_rsp_hdr()

If client send smb2 negotiate request and then send smb1 negotiate
request, init_smb2_rsp_hdr is called for smb1 negotiate request since
need_neg is set to false. This patch ignore smb1 packets after ->need_neg
is set to false.

Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21541
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: avoid field overflow warning

clang warns about a possible field overflow in a memcpy:

In file included from fs/smb/server/smb_common.c:7:
include/linux/fortify-string.h:583:4: error: call to '__write_overflow_field' declared with 'warning' attribute: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror,-Wattribute-warning]
__write_overflow_field(p_size_field, size);

It appears to interpret the "&out[baselen + 4]" as referring to a single
byte of the character array, while the equivalen "out + baselen + 4" is
seen as an offset into the array.

I don't see that kind of warning elsewhere, so just go with the simple
rework.

Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: Use struct_size() helper in ksmbd_negotiate_smb_dialect()

Prefer struct_size() over open-coded versions.

Link: https://github.com/KSPP/linux/issues/160
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: use kzalloc() instead of __GFP_ZERO

Use kzalloc() instead of __GFP_ZERO.

Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

ksmbd: validate smb request protocol id

This patch add the validation for smb request protocol id.
If it is not one of the four ids(SMB1_PROTO_NUMBER, SMB2_PROTO_NUMBER,
SMB2_TRANSFORM_PROTO_NUM, SMB2_COMPRESSION_TRANSFORM_ID), don't allow
processing the request. And this will fix the following KASAN warning
also.

[ 13.905265] BUG: KASAN: slab-out-of-bounds in init_smb2_rsp_hdr+0x1b9/0x1f0
[ 13.905900] Read of size 16 at addr ffff888005fd2f34 by task kworker/0:2/44
...
[ 13.908553] Call Trace:
[ 13.908793] <TASK>
[ 13.908995] dump_stack_lvl+0x33/0x50
[ 13.909369] print_report+0xcc/0x620
[ 13.910870] kasan_report+0xae/0xe0
[ 13.911519] kasan_check_range+0x35/0x1b0
[ 13.911796] init_smb2_rsp_hdr+0x1b9/0x1f0
[ 13.912492] handle_ksmbd_work+0xe5/0x820

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>