Martin Willi 3a5ca85707 can: dev: Move device back to init netns on owning netns delete ... When a non-initial netns is destroyed, the usual policy is to delete all virtual network interfaces contained, but move physical interfaces back to the initial netns. This keeps the physical interface visible on the system. CAN devices are somewhat special, as they define rtnl_link_ops even if they are physical devices. If a CAN interface is moved into a non-initial netns, destroying that netns lets the interface vanish instead of moving it back to the initial netns. default_device_exit() skips CAN interfaces due to having rtnl_link_ops set. Reproducer: ip netns add foo ip link set can0 netns foo ip netns delete foo WARNING: CPU: 1 PID: 84 at net/core/dev.c:11030 ops_exit_list+0x38/0x60 CPU: 1 PID: 84 Comm: kworker/u4:2 Not tainted 5.10.19 #1 Workqueue: netns cleanup_net [<c010e700>] (unwind_backtrace) from [<c010a1d8>] (show_stack+0x10/0x14) [<c010a1d8>] (show_stack) from [<c086dc10>] (dump_stack+0x94/0xa8) [<c086dc10>] (dump_stack) from [<c086b938>] (__warn+0xb8/0x114) [<c086b938>] (__warn) from [<c086ba10>] (warn_slowpath_fmt+0x7c/0xac) [<c086ba10>] (warn_slowpath_fmt) from [<c0629f20>] (ops_exit_list+0x38/0x60) [<c0629f20>] (ops_exit_list) from [<c062a5c4>] (cleanup_net+0x230/0x380) [<c062a5c4>] (cleanup_net) from [<c0142c20>] (process_one_work+0x1d8/0x438) [<c0142c20>] (process_one_work) from [<c0142ee4>] (worker_thread+0x64/0x5a8) [<c0142ee4>] (worker_thread) from [<c0148a98>] (kthread+0x148/0x14c) [<c0148a98>] (kthread) from [<c0100148>] (ret_from_fork+0x14/0x2c) To properly restore physical CAN devices to the initial netns on owning netns exit, introduce a flag on rtnl_link_ops that can be set by drivers. For CAN devices setting this flag, default_device_exit() considers them non-virtual, applying the usual namespace move. The issue was introduced in the commit mentioned below, as at that time CAN devices did not have a dellink() operation. Fixes: e008b5fc8d ("net: Simplfy default_device_exit and improve batching.") Link: https://lore.kernel.org/r/20210302122423.872326-1-martin@strongswan.org Signed-off-by: Martin Willi <martin@strongswan.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>		2021-03-16 08:40:04 +01:00
..
bittiming.c
dev.c
length.c
Makefile
netlink.c	can: dev: Move device back to init netns on owning netns delete	2021-03-16 08:40:04 +01:00
rx-offload.c
skb.c