can: j1939: j1939_tp_tx_dat_new(): fix out-of-bounds memory access

In the j1939_tp_tx_dat_new() function, an out-of-bounds memory access
could occur during the memcpy() operation if the size of skb->cb is
larger than the size of struct j1939_sk_buff_cb. This is because the
memcpy() operation uses the size of skb->cb, leading to a read beyond
the struct j1939_sk_buff_cb.

Updated the memcpy() operation to use the size of struct
j1939_sk_buff_cb instead of the size of skb->cb. This ensures that the
memcpy() operation only reads the memory within the bounds of struct
j1939_sk_buff_cb, preventing out-of-bounds memory access.

Additionally, add a BUILD_BUG_ON() to check that the size of skb->cb
is greater than or equal to the size of struct j1939_sk_buff_cb. This
ensures that the skb->cb buffer is large enough to hold the
j1939_sk_buff_cb structure.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Reported-by: Shuangpeng Bai <sjb7183@psu.edu>
Tested-by: Shuangpeng Bai <sjb7183@psu.edu>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://groups.google.com/g/syzkaller/c/G_LL-C3plRs/m/-8xCi6dCAgAJ
Link: https://lore.kernel.org/all/20230404073128.3173900-1-o.rempel@pengutronix.de
Cc: stable@vger.kernel.org
[mkl: rephrase commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: prevent deadlock by moving j1939_sk_errqueue()

This commit addresses a deadlock situation that can occur in certain
scenarios, such as when running data TP/ETP transfer and subscribing to
the error queue while receiving a net down event. The deadlock involves
locks in the following order:

3
j1939_session_list_lock -> active_session_list_lock
j1939_session_activate
...
j1939_sk_queue_activate_next -> sk_session_queue_lock
...
j1939_xtp_rx_eoma_one

2
j1939_sk_queue_drop_all -> sk_session_queue_lock
...
j1939_sk_netdev_event_netdown -> j1939_socks_lock
j1939_netdev_notify

1
j1939_sk_errqueue -> j1939_socks_lock
__j1939_session_cancel -> active_session_list_lock
j1939_tp_rxtimer

CPU0 CPU1
---- ----
lock(&priv->active_session_list_lock);
lock(&jsk->sk_session_queue_lock);
lock(&priv->active_session_list_lock);
lock(&priv->j1939_socks_lock);

The solution implemented in this commit is to move the
j1939_sk_errqueue() call out of the active_session_list_lock context,
thus preventing the deadlock situation.

Reported-by: syzbot+ee1cd780f69483a8616b@syzkaller.appspotmail.com
Fixes: 5b9272e93f2e ("can: j1939: extend UAPI to notify about RX status")
Co-developed-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/all/20230324130141.2132787-1-o.rempel@pengutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: fix errant WARN_ON_ONCE in j1939_session_deactivate

The conclusion "j1939_session_deactivate() should be called with a
session ref-count of at least 2" is incorrect. In some concurrent
scenarios, j1939_session_deactivate can be called with the session
ref-count less than 2. But there is not any problem because it
will check the session active state before session putting in
j1939_session_deactivate_locked().

Here is the concurrent scenario of the problem reported by syzbot
and my reproduction log.

cpu0 cpu1
j1939_xtp_rx_eoma
j1939_xtp_rx_abort_one
j1939_session_get_by_addr [kref == 2]
j1939_session_get_by_addr [kref == 3]
j1939_session_deactivate [kref == 2]
j1939_session_put [kref == 1]
j1939_session_completed
j1939_session_deactivate
WARN_ON_ONCE(kref < 2)

=====================================================
WARNING: CPU: 1 PID: 21 at net/can/j1939/transport.c:1088 j1939_session_deactivate+0x5f/0x70
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 5.14.0-rc7+ #32
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
RIP: 0010:j1939_session_deactivate+0x5f/0x70
Call Trace:
j1939_session_deactivate_activate_next+0x11/0x28
j1939_xtp_rx_eoma+0x12a/0x180
j1939_tp_recv+0x4a2/0x510
j1939_can_recv+0x226/0x380
can_rcv_filter+0xf8/0x220
can_receive+0x102/0x220
? process_backlog+0xf0/0x2c0
can_rcv+0x53/0xf0
__netif_receive_skb_one_core+0x67/0x90
? process_backlog+0x97/0x2c0
__netif_receive_skb+0x22/0x80

Fixes: 0c71437dd50d ("can: j1939: j1939_session_deactivate(): clarify lifetime of session object")
Reported-by: syzbot+9981a614060dcee6eeca@syzkaller.appspotmail.com
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/all/20210906094200.95868-1-william.xuanziyang@huawei.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

treewide: use get_random_u32_below() instead of deprecated function

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

can: j1939: j1939_session_tx_eoma(): fix debug info

Use "%s" instead of "%p" to print function name in debug info.

Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/all/1664520728-4644-1-git-send-email-zhangchangzhong@huawei.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: transport: j1939_session_skb_drop_old(): spin_unlock_irqrestore() before kfree_skb()

It is not allowed to call kfree_skb() from hardware interrupt context
or with interrupts being disabled. The skb is unlinked from the queue,
so it can be freed after spin_unlock_irqrestore().

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/all/20221027091237.2290111-1-yangyingliang@huawei.com
Cc: stable@vger.kernel.org
[mkl: adjust subject]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_session_destroy(): fix memory leak of skbs

We need to drop skb references taken in j1939_session_skb_queue() when
destroying a session in j1939_session_destroy(). Otherwise those skbs
would be lost.

Link to Syzkaller info and repro: https://forge.ispras.ru/issues/11743.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

V1: https://lore.kernel.org/all/20220708175949.539064-1-pchelkin@ispras.ru

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Suggested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/all/20220805150216.66313-1-pchelkin@ispras.ru
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net-timestamp: convert sk->sk_tskey to atomic_t

UDP sendmsg() can be lockless, this is causing all kinds
of data races.

This patch converts sk->sk_tskey to remove one of these races.

BUG: KCSAN: data-race in __ip_append_data / __ip_append_data

read to 0xffff8881035d4b6c of 4 bytes by task 8877 on cpu 1:
__ip_append_data+0x1c1/0x1de0 net/ipv4/ip_output.c:994
ip_make_skb+0x13f/0x2d0 net/ipv4/ip_output.c:1636
udp_sendmsg+0x12bd/0x14c0 net/ipv4/udp.c:1249
inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg net/socket.c:725 [inline]
____sys_sendmsg+0x39a/0x510 net/socket.c:2413
___sys_sendmsg net/socket.c:2467 [inline]
__sys_sendmmsg+0x267/0x4c0 net/socket.c:2553
__do_sys_sendmmsg net/socket.c:2582 [inline]
__se_sys_sendmmsg net/socket.c:2579 [inline]
__x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

write to 0xffff8881035d4b6c of 4 bytes by task 8880 on cpu 0:
__ip_append_data+0x1d8/0x1de0 net/ipv4/ip_output.c:994
ip_make_skb+0x13f/0x2d0 net/ipv4/ip_output.c:1636
udp_sendmsg+0x12bd/0x14c0 net/ipv4/udp.c:1249
inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:819
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg net/socket.c:725 [inline]
____sys_sendmsg+0x39a/0x510 net/socket.c:2413
___sys_sendmsg net/socket.c:2467 [inline]
__sys_sendmmsg+0x267/0x4c0 net/socket.c:2553
__do_sys_sendmmsg net/socket.c:2582 [inline]
__se_sys_sendmmsg net/socket.c:2579 [inline]
__x64_sys_sendmmsg+0x53/0x60 net/socket.c:2579
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000054d -> 0x0000054e

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8880 Comm: syz-executor.5 Not tainted 5.17.0-rc2-syzkaller-00167-gdcb85f85fa6f-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 09c2d251b707 ("net-timestamp: add key to disambiguate concurrent datagrams")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: j1939: j1939_tp_cmd_recv(): check the dst address of TP.CM_BAM

The TP.CM_BAM message must be sent to the global address [1], so add a
check to drop TP.CM_BAM sent to a non-global address.

Without this patch, the receiver will treat the following packets as
normal RTS/CTS transport:
18EC0102#20090002FF002301
18EB0102#0100000000000000
18EB0102#020000FFFFFFFFFF

[1] SAE-J1939-82 2015 A.3.3 Row 1.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/all/1635431907-15617-4-git-send-email-zhangchangzhong@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_tp_cmd_recv(): ignore abort message in the BAM transport

This patch prevents BAM transport from being closed by receiving abort
message, as specified in SAE-J1939-82 2015 (A.3.3 Row 4).

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/all/1635431907-15617-2-git-send-email-zhangchangzhong@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_xtp_rx_rts_session_new(): abort TP less than 9 bytes

The receiver should abort TP if 'total message size' in TP.CM_RTS and
TP.CM_BAM is less than 9 or greater than 1785 [1], but currently the
j1939 stack only checks the upper bound and the receiver will accept
the following broadcast message:

vcan1 18ECFF00 [8] 20 08 00 02 FF 00 23 01
vcan1 18EBFF00 [8] 01 00 00 00 00 00 00 00
vcan1 18EBFF00 [8] 02 00 FF FF FF FF FF FF

This patch adds check for the lower bound and abort illegal TP.

[1] SAE-J1939-82 A.3.4 Row 2 and A.3.6 Row 6.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/all/1634203601-3460-1-git-send-email-zhangchangzhong@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_xtp_rx_dat_one(): cancel session if receive TP.DT with error length

According to SAE-J1939-21, the data length of TP.DT must be 8 bytes, so
cancel session when receive unexpected TP.DT message.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/all/1632972800-45091-1-git-send-email-zhangchangzhong@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_tp_rxtimer(): fix errant alert in j1939_tp_rxtimer

When the session state is J1939_SESSION_DONE, j1939_tp_rxtimer() will
give an alert "rx timeout, send abort", but do nothing actually. Move
the alert into session active judgment condition, it is more
reasonable.

One of the scenarios is that j1939_tp_rxtimer() execute followed by
j1939_xtp_rx_abort_one(). After j1939_xtp_rx_abort_one(), the session
state is J1939_SESSION_DONE, then j1939_tp_rxtimer() give an alert.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/all/20210906094219.95924-1-william.xuanziyang@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: extend UAPI to notify about RX status

To be able to create applications with user friendly feedback, we need be
able to provide receive status information.

Typical ETP transfer may take seconds or even hours. To give user some
clue or show a progress bar, the stack should push status updates.
Same as for the TX information, the socket error queue will be used with
following new signals:
- J1939_EE_INFO_RX_RTS - received and accepted request to send signal.
- J1939_EE_INFO_RX_DPO - received data package offset signal
- J1939_EE_INFO_RX_ABORT - RX session was aborted

Instead of completion signal, user will get data package.
To activate this signals, application should set
SOF_TIMESTAMPING_RX_SOFTWARE to the SO_TIMESTAMPING socket option. This
will avoid unpredictable application behavior for the old software.

Link: https://lore.kernel.org/r/20210707094854.30781-3-o.rempel@pengutronix.de
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: rename J1939_ERRQUEUE_* to J1939_ERRQUEUE_TX_*

Prepare the world for the J1939_ERRQUEUE_RX_ version

Link: https://lore.kernel.org/r/20210707094854.30781-2-o.rempel@pengutronix.de
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_session_tx_dat(): fix typo

This patch fixes a typo in the j1939_session_tx_dat() function.

Link: https://lore.kernel.org/r/20210729113917.1655492-1-mkl@pengutronix.de
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_xtp_rx_dat_one(): use separate pointer for session skb control buffer

In the j1939_xtp_rx_dat_one() function, there are 2 variables (skb and
se_skb) holding a skb. The control buffer of the skbs is accessed one
after the other, but using the same "skcb" variable.

To avoid confusion introduce a new variable "se_skcb" to access the
se_skb's control buffer as done in the rest of this file, too.

Cc: Robin van der Gracht <robin@protonic.nl>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20210616102811.2449426-6-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_session_tx_dat(): use consistent name se_skcb for session skb control buffer

This patch changes the name of the "skcb" variable in
j1939_session_tx_dat() to "se_skcb" as it's the session skb's control
buffer. The same name is used in other functions for the session skb's
control buffer.

Cc: Robin van der Gracht <robin@protonic.nl>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20210616102811.2449426-5-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_session_completed(): use consistent name se_skb for the session skb

This patch changes the name of the "skb" variable in
j1939_session_completed() to "se_skb" as it's the session skb. The
same name is used in other functions for the session skb.

Cc: Robin van der Gracht <robin@protonic.nl>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20210616102811.2449426-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: replace fall through comment by fallthrough pseudo-keyword

Replace the existing /* fall through */ comments the new
pseudo-keyword macro fallthrough.

Cc: Robin van der Gracht <robin@protonic.nl>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20210616102811.2449426-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: fix checkpatch warnings

This patch fixes a checkpatch warning about a long line and wrong
indention.

Cc: Robin van der Gracht <robin@protonic.nl>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20210616102811.2449426-2-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_xtp_rx_dat_one(): fix rxtimer value between consecutive TP.DT to 750ms

For receive side, the max time interval between two consecutive TP.DT
should be 750ms.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/1625569210-47506-1-git-send-email-zhangchangzhong@huawei.com
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: j1939_session_deactivate(): clarify lifetime of session object

The j1939_session_deactivate() is decrementing the session ref-count and
potentially can free() the session. This would cause use-after-free
situation.

However, the code calling j1939_session_deactivate() does always hold
another reference to the session, so that it would not be free()ed in
this code path.

This patch adds a comment to make this clear and a WARN_ON, to ensure
that future changes will not violate this requirement. Further this
patch avoids dereferencing the session pointer as a precaution to avoid
use-after-free if the session is actually free()ed.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/20210714111602.24021-1-o.rempel@pengutronix.de
Reported-by: Xiaochen Zou <xzou017@ucr.edu>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: fix Use-after-Free, hold skb ref while in use

This patch fixes a Use-after-Free found by the syzbot.

The problem is that a skb is taken from the per-session skb queue,
without incrementing the ref count. This leads to a Use-after-Free if
the skb is taken concurrently from the session queue due to a CTS.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/20210521115720.7533-1-o.rempel@pengutronix.de
Cc: Hillf Danton <hdanton@sina.com>
Cc: linux-stable <stable@vger.kernel.org>
Reported-by: syzbot+220c1a29987a9a490903@syzkaller.appspotmail.com
Reported-by: syzbot+45199c1b73b4013525cf@syzkaller.appspotmail.com
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

net: j1939: j1939_session_fresh_new(): fix missing initialization of skbcnt

This patch add the initialization of skbcnt, similar to:

e009f95b1543 can: j1935: j1939_tp_tx_dat_new(): fix missing initialization of skbcnt

Let's play save and initialize this skbcnt as well.

Suggested-by: Jakub Kicinski <kuba@kernel.org>
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1935: j1939_tp_tx_dat_new(): fix missing initialization of skbcnt

This fixes an uninit-value warning:
BUG: KMSAN: uninit-value in can_receive+0x26b/0x630 net/can/af_can.c:650

Reported-and-tested-by: syzbot+3f3837e61a48d32b495f@syzkaller.appspotmail.com
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Cc: Robin van der Gracht <robin@protonic.nl>
Cc: Oleksij Rempel <linux@rempel-privat.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://lore.kernel.org/r/20201008061821.24663-1-xiyou.wangcong@gmail.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

can: j1939: add rxtimer for multipacket broadcast session

According to SAE J1939/21 (Chapter 5.12.3 and APPENDIX C), for transmit side
the required time interval between packets of a multipacket broadcast message
is 50 to 200 ms, the responder shall use a timeout of 250ms (provides margin
allowing for the maximumm spacing of 200ms). For receive side a timeout will
occur when a time of greater than 750 ms elapsed between two message packets
when more packets were expected.

So this patch fix and add rxtimer for multipacket broadcast session.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1596599425-5534-5-git-send-email-zhangchangzhong@huawei.com
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: abort multipacket broadcast session when timeout occurs

If timeout occurs, j1939_tp_rxtimer() first calls hrtimer_start() to restart
rxtimer, and then calls __j1939_session_cancel() to set session->state =
J1939_SESSION_WAITING_ABORT. At next timeout expiration, because of the
J1939_SESSION_WAITING_ABORT session state j1939_tp_rxtimer() will call
j1939_session_deactivate_activate_next() to deactivate current session, and
rxtimer won't be set.

But for multipacket broadcast session, __j1939_session_cancel() don't set
session->state = J1939_SESSION_WAITING_ABORT, thus current session won't be
deactivate and hrtimer_start() is called to start new rxtimer again and again.

So fix it by moving session->state = J1939_SESSION_WAITING_ABORT out of if
(!j1939_cb_is_broadcast(&session->skcb)) statement.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1596599425-5534-4-git-send-email-zhangchangzhong@huawei.com
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: cancel rxtimer on multipacket broadcast session complete

If j1939_xtp_rx_dat_one() receive last frame of multipacket broadcast message,
j1939_session_timers_cancel() should be called to cancel rxtimer.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1596599425-5534-3-git-send-email-zhangchangzhong@huawei.com
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: fix support for multipacket broadcast message

Currently j1939_tp_im_involved_anydir() in j1939_tp_recv() check the previously
set flags J1939_ECU_LOCAL_DST and J1939_ECU_LOCAL_SRC of incoming skb, thus
multipacket broadcast message was aborted by receive side because it may come
from remote ECUs and have no exact dst address. Similarly, j1939_tp_cmd_recv()
and j1939_xtp_rx_dat() didn't process broadcast message.

So fix it by checking and process broadcast message in j1939_tp_recv(),
j1939_tp_cmd_recv() and j1939_xtp_rx_dat().

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Link: https://lore.kernel.org/r/1596599425-5534-2-git-send-email-zhangchangzhong@huawei.com
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: transport: j1939_xtp_rx_dat_one(): compare own packets to detect corruptions

Since the stack relays on receiving own packets, it was overwriting own
transmit buffer from received packets.

At least theoretically, the received echo buffer can be corrupt or
changed and the session partner can request to resend previous data. In
this case we will re-send bad data.

With this patch we will stop to overwrite own TX buffer and use it for
sanity checking.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20200807105200.26441-6-o.rempel@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: transport: add j1939_session_skb_find_by_offset() function

Sometimes it makes no sense to search the skb by pkt.dpo, since we need
next the skb within the transaction block. This may happen if we have an
ETP session with CTS set to less than 255 packets.

After this patch, we will be able to work with ETP sessions where the
block size (ETP.CM_CTS byte 2) is less than 255 packets.

Reported-by: Henrique Figueira <henrislip@gmail.com>
Reported-by: https://github.com/linux-can/can-utils/issues/228
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20200807105200.26441-5-o.rempel@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: transport: j1939_session_tx_dat(): fix use-after-free read in j1939_tp_txtimer()

The current stack implementation do not support ECTS requests of not
aligned TP sized blocks.

If ECTS will request a block with size and offset spanning two TP
blocks, this will cause memcpy() to read beyond the queued skb (which
does only contain one TP sized block).

Sometimes KASAN will detect this read if the memory region beyond the
skb was previously allocated and freed. In other situations it will stay
undetected. The ETP transfer in any case will be corrupted.

This patch adds a sanity check to avoid this kind of read and abort the
session with error J1939_XTP_ABORT_ECTS_TOO_BIG.

Reported-by: syzbot+5322482fe520b02aea30@syzkaller.appspotmail.com
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Cc: linux-stable <stable@vger.kernel.org> # >= v5.4
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20200807105200.26441-3-o.rempel@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: transport: j1939_simple_recv(): ignore local J1939 messages send not by J1939 stack

In current J1939 stack implementation, we process all locally send
messages as own messages. Even if it was send by CAN_RAW socket.

To reproduce it use following commands:
testj1939 -P -r can0:0x80 &
cansend can0 18238040#0123

This step will trigger false positive not critical warning:
j1939_simple_recv: Received already invalidated message

With this patch we add additional check to make sure, related skb is own
echo message.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20200807105200.26441-2-o.rempel@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: warn if resources are still linked on destroy

j1939_session_destroy() and __j1939_priv_release() should be called only
if session, ecu or socket are not linked or used by any one else. If at
least one of these resources is linked, then the reference counting is
broken somewhere.

This warning will be triggered before KASAN will do, and will make it
easier to debug initial issue. This works on platforms without KASAN
support.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>

can: j1939: transport: j1939_cancel_active_session(): use hrtimer_try_to_cancel() instead of hrtimer_cancel()

This part of the code protected by lock used in the hrtimer as well.
Using hrtimer_cancel() will trigger dead lock.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>

can: j1939: make sure socket is held as long as session exists

We link the socket to the session to be able provide socket specific
notifications. For example messages over error queue.

We need to keep the socket held, while we have a reference to it.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>

can: j1939: transport: make sure the aborted session will be deactivated only once

j1939_session_cancel() was modifying session->state without protecting
it by locks and without checking actual state of the session.

This patch moves j1939_tp_set_rxtimeout() into j1939_session_cancel()
and adds the missing locking.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>

can: j1939: transport: j1939_xtp_rx_eoma_one(): Add sanity check for correct total message size

We were sending malformed EOMA with total message size set to 0. This
issue has been fixed in the previous patch.

In this patch a sanity check is added to the RX path and a error message
is displayed.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: transport: j1939_session_fresh_new(): make sure EOMA is send with the total message size set

We were sending malformed EOMA messageswith total message size set to 0.

This patch fixes the bug.

Reported-by: https://github.com/linux-can/can-utils/issues/159
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: add support of SAE J1939 protocol

SAE J1939 is the vehicle bus recommended practice used for communication
and diagnostics among vehicle components. Originating in the car and
heavy-duty truck industry in the United States, it is now widely used in
other parts of the world.

J1939, ISO 11783 and NMEA 2000 all share the same high level protocol.
SAE J1939 can be considered the replacement for the older SAE J1708 and
SAE J1587 specifications.

Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Elenita Hinds <ecathinds@gmail.com>
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Maxime Jayat <maxime.jayat@mobile-devices.fr>
Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>