shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-06 19:08:57 +09:00
Code Issues Packages Projects Releases Wiki Activity

can: netlink: can_changelink(): allow disabling of automatic restart

Browse Source 
commit 8e93ac51e4c6dc399fad59ec21f55f2cfb46d27c upstream.

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] 13ce5d4632

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Marc Kleine-Budde
2025-10-20 11:51:03 +02:00
committed by Greg Kroah-Hartman
parent a9da00c9ce
commit 356c7fdf68
1 changed files with 4 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/net/can/dev/netlink.c
View File

@@ -285,7 +285,9 @@ 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;
@@ -294,7 +296,7 @@ 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]) {