diff options
| author | Marc Kleine-Budde <mkl@pengutronix.de> | 2025-10-20 11:51:03 +0200 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2025-10-20 17:20:12 +0200 |
| commit | 8e93ac51e4c6dc399fad59ec21f55f2cfb46d27c (patch) | |
| tree | 8cef7f9943abc896631176f0d9b8361abe560d40 /drivers/net/can/dev/netlink.c | |
| parent | 942b3c611067385849a912135175a66f25b7b1cb (diff) | |
can: netlink: can_changelink(): allow disabling of automatic restart
Since the commit c1f3f9797c1f ("can: netlink: can_changelink(): fix NULL
pointer deref of struct can_priv::do_set_mode"), the automatic restart
delay can only be set for devices that implement the restart handler struct
can_priv::do_set_mode. As it makes no sense to configure a automatic
restart for devices that doesn't support it.
However, since systemd commit 13ce5d4632e3 ("network/can: properly handle
CAN.RestartSec=0") [1], systemd-networkd correctly handles a restart delay
of "0" (i.e. the restart is disabled). Which means that a disabled restart
is always configured in the kernel.
On systems with both changes active this causes that CAN interfaces that
don't implement a restart handler cannot be brought up by systemd-networkd.
Solve this problem by allowing a delay of "0" to be configured, even if the
device does not implement a restart handler.
[1] https://github.com/systemd/systemd/commit/13ce5d4632e395521e6205c954493c7fc1c4c6e0
Cc: stable@vger.kernel.org
Cc: Andrei Lalaev <andrey.lalaev@gmail.com>
Reported-by: Marc Kleine-Budde <mkl@pengutronix.de>
Closes: https://lore.kernel.org/all/20251020-certain-arrogant-vole-of-sunshine-141841-mkl@pengutronix.de
Fixes: c1f3f9797c1f ("can: netlink: can_changelink(): fix NULL pointer deref of struct can_priv::do_set_mode")
Link: https://patch.msgid.link/20251020-netlink-fix-restart-v1-1-3f53c7f8520b@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/dev/netlink.c')
| -rw-r--r-- | drivers/net/can/dev/netlink.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index 0591406b6f32..6f83b87d54fc 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -452,7 +452,9 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[], } if (data[IFLA_CAN_RESTART_MS]) { - if (!priv->do_set_mode) { + unsigned int restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); + + if (restart_ms != 0 && !priv->do_set_mode) { NL_SET_ERR_MSG(extack, "Device doesn't support restart from Bus Off"); return -EOPNOTSUPP; @@ -461,7 +463,7 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[], /* Do not allow changing restart delay while running */ if (dev->flags & IFF_UP) return -EBUSY; - priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]); + priv->restart_ms = restart_ms; } if (data[IFLA_CAN_RESTART]) { |