Oliver Hartkopp 051737439e can: isotp: fix race between isotp_sendsmg() and isotp_release()
As discussed with Dae R. Jeong and Hillf Danton here [1] the sendmsg()
function in isotp.c might get into a race condition when restoring the
former tx.state from the old_state.

Remove the old_state concept and implement proper locking for the
ISOTP_IDLE transitions in isotp_sendmsg(), inspired by a
simplification idea from Hillf Danton.

Introduce a new tx.state ISOTP_SHUTDOWN and use the same locking
mechanism from isotp_release() which resolves a potential race between
isotp_sendsmg() and isotp_release().

[1] https://lore.kernel.org/linux-can/ZB%2F93xJxq%2FBUqAgG@dragonet

v1: https://lore.kernel.org/all/20230331102114.15164-1-socketcan@hartkopp.net
v2: https://lore.kernel.org/all/20230331123600.3550-1-socketcan@hartkopp.net
    take care of signal interrupts for wait_event_interruptible() in
    isotp_release()
v3: https://lore.kernel.org/all/20230331130654.9886-1-socketcan@hartkopp.net
    take care of signal interrupts for wait_event_interruptible() in
    isotp_sendmsg() in the wait_tx_done case
v4: https://lore.kernel.org/all/20230331131935.21465-1-socketcan@hartkopp.net
    take care of signal interrupts for wait_event_interruptible() in
    isotp_sendmsg() in ALL cases

Cc: Dae R. Jeong <threeearcat@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Fixes: 4f027cba82 ("can: isotp: split tx timer into transmission and timeout")
Link: https://lore.kernel.org/all/20230331131935.21465-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
[mkl: rephrase commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2023-04-05 11:16:37 +02:00
2023-03-26 14:40:20 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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