<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/can, branch v6.3-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2023-02-09T20:25:40+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-02-09T20:05:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8697a258ae24703267d2a37d91ab757c91ef027e'/>
<id>8697a258ae24703267d2a37d91ab757c91ef027e</id>
<content type='text'>
net/devlink/leftover.c / net/core/devlink.c:
  565b4824c39f ("devlink: change port event netdev notifier from per-net to global")
  f05bd8ebeb69 ("devlink: move code to a dedicated directory")
  687125b5799c ("devlink: split out core code")
https://lore.kernel.org/all/20230208094657.379f2b1a@canb.auug.org.au/

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
net/devlink/leftover.c / net/core/devlink.c:
  565b4824c39f ("devlink: change port event netdev notifier from per-net to global")
  f05bd8ebeb69 ("devlink: move code to a dedicated directory")
  687125b5799c ("devlink: split out core code")
https://lore.kernel.org/all/20230208094657.379f2b1a@canb.auug.org.au/

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: raw: use temp variable instead of rolling back config</title>
<updated>2023-02-08T20:53:24+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-02-03T09:08:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f2f527d595963aa86464ca3e05ec27dd5153d56e'/>
<id>f2f527d595963aa86464ca3e05ec27dd5153d56e</id>
<content type='text'>
Introduce a temporary variable to check for an invalid configuration
attempt from user space. Before this patch the value was copied to
the real config variable and rolled back in the case of an error.

Suggested-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230203090807.97100-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce a temporary variable to check for an invalid configuration
attempt from user space. Before this patch the value was copied to
the real config variable and rolled back in the case of an error.

Suggested-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230203090807.97100-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'linux-can-next-for-6.3-20230206' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next</title>
<updated>2023-02-07T14:54:09+00:00</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2023-02-07T14:54:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=61d731e6538dc44abf2dca6e77098ec6e85f7cc2'/>
<id>61d731e6538dc44abf2dca6e77098ec6e85f7cc2</id>
<content type='text'>
Marc Kleine-Budde says:

====================
pull-request: can-next 2023-02-06

this is a pull request of 47 patches for net-next/master.

The first two patch is by Oliver Hartkopp. One adds missing error
checking to the CAN_GW protocol, the other adds a missing CAN address
family check to the CAN ISO TP protocol.

Thomas Kopp contributes a performance optimization to the mcp251xfd
driver.

The next 11 patches are by Geert Uytterhoeven and add support for
R-Car V4H systems to the rcar_canfd driver.

Stephane Grosjean and Lukas Magel contribute 8 patches to the peak_usb
driver, which add support for configurable CAN channel ID.

The last 17 patches are by me and target the CAN bit timing
configuration. The bit timing is cleaned up, error messages are
improved and forwarded to user space via NL_SET_ERR_MSG_FMT() instead
of netdev_err(), and the SJW handling is updated, including the
definition of a new default value that will benefit CAN-FD
controllers, by increasing their oscillator tolerance.

* tag 'linux-can-next-for-6.3-20230206' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next: (47 commits)
  can: bittiming: can_validate_bitrate(): report error via netlink
  can: bittiming: can_calc_bittiming(): convert from netdev_err() to NL_SET_ERR_MSG_FMT()
  can: bittiming: can_calc_bittiming(): clean up SJW handling
  can: bittiming: can_sjw_set_default(): use Phase Seg2 / 2 as default for SJW
  can: bittiming: can_sjw_check(): check that SJW is not longer than either Phase Buffer Segment
  can: bittiming: can_sjw_check(): report error via netlink and harmonize error value
  can: bittiming: can_fixup_bittiming(): report error via netlink and harmonize error value
  can: bittiming: factor out can_sjw_set_default() and can_sjw_check()
  can: bittiming: can_changelink() pass extack down callstack
  can: netlink: can_changelink(): convert from netdev_err() to NL_SET_ERR_MSG_FMT()
  can: netlink: can_validate(): validate sample point for CAN and CAN-FD
  can: dev: register_candev(): bail out if both fixed bit rates and bit timing constants are provided
  can: dev: register_candev(): ensure that bittiming const are valid
  can: bittiming: can_get_bittiming(): use direct return and remove unneeded else
  can: bittiming: can_fixup_bittiming(): set effective tq
  can: bittiming: can_fixup_bittiming(): use CAN_SYNC_SEG instead of 1
  can: bittiming(): replace open coded variants of can_bit_time()
  can: peak_usb: Reorder include directives alphabetically
  can: peak_usb: align CAN channel ID format in log with sysfs attribute
  can: peak_usb: export PCAN CAN channel ID as sysfs device attribute
  ...
====================

Link: https://lore.kernel.org/r/20230206131620.2758724-1-mkl@pengutronix.de
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Marc Kleine-Budde says:

====================
pull-request: can-next 2023-02-06

this is a pull request of 47 patches for net-next/master.

The first two patch is by Oliver Hartkopp. One adds missing error
checking to the CAN_GW protocol, the other adds a missing CAN address
family check to the CAN ISO TP protocol.

Thomas Kopp contributes a performance optimization to the mcp251xfd
driver.

The next 11 patches are by Geert Uytterhoeven and add support for
R-Car V4H systems to the rcar_canfd driver.

Stephane Grosjean and Lukas Magel contribute 8 patches to the peak_usb
driver, which add support for configurable CAN channel ID.

The last 17 patches are by me and target the CAN bit timing
configuration. The bit timing is cleaned up, error messages are
improved and forwarded to user space via NL_SET_ERR_MSG_FMT() instead
of netdev_err(), and the SJW handling is updated, including the
definition of a new default value that will benefit CAN-FD
controllers, by increasing their oscillator tolerance.

* tag 'linux-can-next-for-6.3-20230206' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next: (47 commits)
  can: bittiming: can_validate_bitrate(): report error via netlink
  can: bittiming: can_calc_bittiming(): convert from netdev_err() to NL_SET_ERR_MSG_FMT()
  can: bittiming: can_calc_bittiming(): clean up SJW handling
  can: bittiming: can_sjw_set_default(): use Phase Seg2 / 2 as default for SJW
  can: bittiming: can_sjw_check(): check that SJW is not longer than either Phase Buffer Segment
  can: bittiming: can_sjw_check(): report error via netlink and harmonize error value
  can: bittiming: can_fixup_bittiming(): report error via netlink and harmonize error value
  can: bittiming: factor out can_sjw_set_default() and can_sjw_check()
  can: bittiming: can_changelink() pass extack down callstack
  can: netlink: can_changelink(): convert from netdev_err() to NL_SET_ERR_MSG_FMT()
  can: netlink: can_validate(): validate sample point for CAN and CAN-FD
  can: dev: register_candev(): bail out if both fixed bit rates and bit timing constants are provided
  can: dev: register_candev(): ensure that bittiming const are valid
  can: bittiming: can_get_bittiming(): use direct return and remove unneeded else
  can: bittiming: can_fixup_bittiming(): set effective tq
  can: bittiming: can_fixup_bittiming(): use CAN_SYNC_SEG instead of 1
  can: bittiming(): replace open coded variants of can_bit_time()
  can: peak_usb: Reorder include directives alphabetically
  can: peak_usb: align CAN channel ID format in log with sysfs attribute
  can: peak_usb: export PCAN CAN channel ID as sysfs device attribute
  ...
====================

Link: https://lore.kernel.org/r/20230206131620.2758724-1-mkl@pengutronix.de
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: do not wait 250 ms if the same addr was already claimed</title>
<updated>2023-02-07T14:00:22+00:00</updated>
<author>
<name>Devid Antonio Filoni</name>
<email>devid.filoni@egluetechnologies.com</email>
</author>
<published>2022-11-25T17:04:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4ae5e1e97c44f4654516c1d41591a462ed62fa7b'/>
<id>4ae5e1e97c44f4654516c1d41591a462ed62fa7b</id>
<content type='text'>
The ISO 11783-5 standard, in "4.5.2 - Address claim requirements", states:
  d) No CF shall begin, or resume, transmission on the network until 250
     ms after it has successfully claimed an address except when
     responding to a request for address-claimed.

But "Figure 6" and "Figure 7" in "4.5.4.2 - Address-claim
prioritization" show that the CF begins the transmission after 250 ms
from the first AC (address-claimed) message even if it sends another AC
message during that time window to resolve the address contention with
another CF.

As stated in "4.4.2.3 - Address-claimed message":
  In order to successfully claim an address, the CF sending an address
  claimed message shall not receive a contending claim from another CF
  for at least 250 ms.

As stated in "4.4.3.2 - NAME management (NM) message":
  1) A commanding CF can
     d) request that a CF with a specified NAME transmit the address-
        claimed message with its current NAME.
  2) A target CF shall
     d) send an address-claimed message in response to a request for a
        matching NAME

Taking the above arguments into account, the 250 ms wait is requested
only during network initialization.

Do not restart the timer on AC message if both the NAME and the address
match and so if the address has already been claimed (timer has expired)
or the AC message has been sent to resolve the contention with another
CF (timer is still running).

Signed-off-by: Devid Antonio Filoni &lt;devid.filoni@egluetechnologies.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20221125170418.34575-1-devid.filoni@egluetechnologies.com
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The ISO 11783-5 standard, in "4.5.2 - Address claim requirements", states:
  d) No CF shall begin, or resume, transmission on the network until 250
     ms after it has successfully claimed an address except when
     responding to a request for address-claimed.

But "Figure 6" and "Figure 7" in "4.5.4.2 - Address-claim
prioritization" show that the CF begins the transmission after 250 ms
from the first AC (address-claimed) message even if it sends another AC
message during that time window to resolve the address contention with
another CF.

As stated in "4.4.2.3 - Address-claimed message":
  In order to successfully claim an address, the CF sending an address
  claimed message shall not receive a contending claim from another CF
  for at least 250 ms.

As stated in "4.4.3.2 - NAME management (NM) message":
  1) A commanding CF can
     d) request that a CF with a specified NAME transmit the address-
        claimed message with its current NAME.
  2) A target CF shall
     d) send an address-claimed message in response to a request for a
        matching NAME

Taking the above arguments into account, the 250 ms wait is requested
only during network initialization.

Do not restart the timer on AC message if both the NAME and the address
match and so if the address has already been claimed (timer has expired)
or the AC message has been sent to resolve the contention with another
CF (timer is still running).

Signed-off-by: Devid Antonio Filoni &lt;devid.filoni@egluetechnologies.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20221125170418.34575-1-devid.filoni@egluetechnologies.com
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: isotp: check CAN address family in isotp_bind()</title>
<updated>2023-02-02T14:42:10+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-01-04T20:18:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c6adf659a8ba85913e16a571d5a9bcd17d3d1234'/>
<id>c6adf659a8ba85913e16a571d5a9bcd17d3d1234</id>
<content type='text'>
Add missing check to block non-AF_CAN binds.

Syzbot created some code which matched the right sockaddr struct size
but used AF_XDP (0x2C) instead of AF_CAN (0x1D) in the address family
field:

bind$xdp(r2, &amp;(0x7f0000000540)={0x2c, 0x0, r4, 0x0, r2}, 0x10)
                                ^^^^
This has no funtional impact but the userspace should be notified about
the wrong address family field content.

Link: https://syzkaller.appspot.com/text?tag=CrashLog&amp;x=11ff9d8c480000
Reported-by: syzbot+5aed6c3aaba661f5b917@syzkaller.appspotmail.com
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230104201844.13168-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add missing check to block non-AF_CAN binds.

Syzbot created some code which matched the right sockaddr struct size
but used AF_XDP (0x2C) instead of AF_CAN (0x1D) in the address family
field:

bind$xdp(r2, &amp;(0x7f0000000540)={0x2c, 0x0, r4, 0x0, r2}, 0x10)
                                ^^^^
This has no funtional impact but the userspace should be notified about
the wrong address family field content.

Link: https://syzkaller.appspot.com/text?tag=CrashLog&amp;x=11ff9d8c480000
Reported-by: syzbot+5aed6c3aaba661f5b917@syzkaller.appspotmail.com
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230104201844.13168-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: gw: give feedback on missing CGW_FLAGS_CAN_IIF_TX_OK flag</title>
<updated>2023-02-02T14:42:10+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-01-25T05:54:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2a30b2bd01c23a7eeace3a3f82c2817227099805'/>
<id>2a30b2bd01c23a7eeace3a3f82c2817227099805</id>
<content type='text'>
To send CAN traffic back to the incoming interface a special flag has to
be set. When creating a routing job for identical interfaces without this
flag the rule is created but has no effect.

This patch adds an error return value in the case that the CAN interfaces
are identical but the CGW_FLAGS_CAN_IIF_TX_OK flag was not set.

Reported-by: Jannik Hartung &lt;jannik.hartung@tu-bs.de&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230125055407.2053-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To send CAN traffic back to the incoming interface a special flag has to
be set. When creating a routing job for identical interfaces without this
flag the rule is created but has no effect.

This patch adds an error return value in the case that the CAN interfaces
are identical but the CGW_FLAGS_CAN_IIF_TX_OK flag was not set.

Reported-by: Jannik Hartung &lt;jannik.hartung@tu-bs.de&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230125055407.2053-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: isotp: split tx timer into transmission and timeout</title>
<updated>2023-02-02T09:33:26+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-01-04T14:57:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4f027cba8216f42a18b544842efab134f8b1f9f4'/>
<id>4f027cba8216f42a18b544842efab134f8b1f9f4</id>
<content type='text'>
The timer for the transmission of isotp PDUs formerly had two functions:
1. send two consecutive frames with a given time gap
2. monitor the timeouts for flow control frames and the echo frames

This led to larger txstate checks and potentially to a problem discovered
by syzbot which enabled the panic_on_warn feature while testing.

The former 'txtimer' function is split into 'txfrtimer' and 'txtimer'
to handle the two above functionalities with separate timer callbacks.

The two simplified timers now run in one-shot mode and make the state
transitions (especially with isotp_rcv_echo) better understandable.

Fixes: 866337865f37 ("can: isotp: fix tx state handling for echo tx processing")
Reported-by: syzbot+5aed6c3aaba661f5b917@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org # &gt;= v6.0
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230104145701.2422-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The timer for the transmission of isotp PDUs formerly had two functions:
1. send two consecutive frames with a given time gap
2. monitor the timeouts for flow control frames and the echo frames

This led to larger txstate checks and potentially to a problem discovered
by syzbot which enabled the panic_on_warn feature while testing.

The former 'txtimer' function is split into 'txfrtimer' and 'txtimer'
to handle the two above functionalities with separate timer callbacks.

The two simplified timers now run in one-shot mode and make the state
transitions (especially with isotp_rcv_echo) better understandable.

Fixes: 866337865f37 ("can: isotp: fix tx state handling for echo tx processing")
Reported-by: syzbot+5aed6c3aaba661f5b917@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org # &gt;= v6.0
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230104145701.2422-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: isotp: handle wait_event_interruptible() return values</title>
<updated>2023-02-02T09:33:26+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-01-12T19:23:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=823b2e42720f96f277940c37ea438b7c5ead51a4'/>
<id>823b2e42720f96f277940c37ea438b7c5ead51a4</id>
<content type='text'>
When wait_event_interruptible() has been interrupted by a signal the
tx.state value might not be ISOTP_IDLE. Force the state machines
into idle state to inhibit the timer handlers to continue working.

Fixes: 866337865f37 ("can: isotp: fix tx state handling for echo tx processing")
Cc: stable@vger.kernel.org
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230112192347.1944-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When wait_event_interruptible() has been interrupted by a signal the
tx.state value might not be ISOTP_IDLE. Force the state machines
into idle state to inhibit the timer handlers to continue working.

Fixes: 866337865f37 ("can: isotp: fix tx state handling for echo tx processing")
Cc: stable@vger.kernel.org
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230112192347.1944-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: raw: fix CAN FD frame transmissions over CAN XL devices</title>
<updated>2023-02-02T09:33:26+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-01-31T10:56:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3793301cbaa4a62d83e21f685307da7671f812ab'/>
<id>3793301cbaa4a62d83e21f685307da7671f812ab</id>
<content type='text'>
A CAN XL device is always capable to process CAN FD frames. The former
check when sending CAN FD frames relied on the existence of a CAN FD
device and did not check for a CAN XL device that would be correct
too.

With this patch the CAN FD feature is enabled automatically when CAN
XL is switched on - and CAN FD cannot be switch off while CAN XL is
enabled.

This precondition also leads to a clean up and reduction of checks in
the hot path in raw_rcv() and raw_sendmsg(). Some conditions are
reordered to handle simple checks first.

changes since v1: https://lore.kernel.org/all/20230131091012.50553-1-socketcan@hartkopp.net
- fixed typo: devive -&gt; device
changes since v2: https://lore.kernel.org/all/20230131091824.51026-1-socketcan@hartkopp.net/
- reorder checks in if statements to handle simple checks first

Fixes: 626332696d75 ("can: raw: add CAN XL support")
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230131105613.55228-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A CAN XL device is always capable to process CAN FD frames. The former
check when sending CAN FD frames relied on the existence of a CAN FD
device and did not check for a CAN XL device that would be correct
too.

With this patch the CAN FD feature is enabled automatically when CAN
XL is switched on - and CAN FD cannot be switch off while CAN XL is
enabled.

This precondition also leads to a clean up and reduction of checks in
the hot path in raw_rcv() and raw_sendmsg(). Some conditions are
reordered to handle simple checks first.

changes since v1: https://lore.kernel.org/all/20230131091012.50553-1-socketcan@hartkopp.net
- fixed typo: devive -&gt; device
changes since v2: https://lore.kernel.org/all/20230131091824.51026-1-socketcan@hartkopp.net/
- reorder checks in if statements to handle simple checks first

Fixes: 626332696d75 ("can: raw: add CAN XL support")
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230131105613.55228-1-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: fix errant WARN_ON_ONCE in j1939_session_deactivate</title>
<updated>2023-02-02T09:33:26+00:00</updated>
<author>
<name>Ziyang Xuan</name>
<email>william.xuanziyang@huawei.com</email>
</author>
<published>2021-09-06T09:42:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d0553680f94c49bbe0e39eb50d033ba563b4212d'/>
<id>d0553680f94c49bbe0e39eb50d033ba563b4212d</id>
<content type='text'>
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 &lt; 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 &lt;william.xuanziyang@huawei.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20210906094200.95868-1-william.xuanziyang@huawei.com
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt; 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 &lt;william.xuanziyang@huawei.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20210906094200.95868-1-william.xuanziyang@huawei.com
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
</feed>
