From e93c9378e33f68b61ea9318580d841caa22fb9ea Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Wed, 10 May 2023 16:46:21 +0200 Subject: devlink: change per-devlink netdev notifier to static one The commit 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") changed original per-net notifier to be per-devlink instance. That fixed the issue of non-receiving events of netdev uninit if that moved to a different namespace. That worked fine in -net tree. However, later on when commit ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") and commit 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") were merged, a deadlock was introduced when removing a namespace with devlink instance with another nested instance. Here there is the bad flow example resulting in deadlock with mlx5: net_cleanup_work -> cleanup_net (takes down_read(&pernet_ops_rwsem) -> devlink_pernet_pre_exit() -> devlink_reload() -> mlx5_devlink_reload_down() -> mlx5_unload_one_devl_locked() -> mlx5_detach_device() -> del_adev() -> mlx5e_remove() -> mlx5e_destroy_devlink() -> devlink_free() -> unregister_netdevice_notifier() (takes down_write(&pernet_ops_rwsem) Steps to reproduce: $ modprobe mlx5_core $ ip netns add ns1 $ devlink dev reload pci/0000:08:00.0 netns ns1 $ ip netns del ns1 Resolve this by converting the notifier from per-devlink instance to a static one registered during init phase and leaving it registered forever. Use this notifier for all devlink port instances created later on. Note what a tree needs this fix only in case all of the cited fixes commits are present. Reported-by: Moshe Shemesh Fixes: 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") Fixes: ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") Fixes: 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") Signed-off-by: Jiri Pirko Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230510144621.932017-1-jiri@resnulli.us Signed-off-by: Jakub Kicinski --- net/devlink/core.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'net/devlink/core.c') diff --git a/net/devlink/core.c b/net/devlink/core.c index 777b091ef74d..0e58eee44bdb 100644 --- a/net/devlink/core.c +++ b/net/devlink/core.c @@ -204,11 +204,6 @@ struct devlink *devlink_alloc_ns(const struct devlink_ops *ops, if (ret < 0) goto err_xa_alloc; - devlink->netdevice_nb.notifier_call = devlink_port_netdevice_event; - ret = register_netdevice_notifier(&devlink->netdevice_nb); - if (ret) - goto err_register_netdevice_notifier; - devlink->dev = dev; devlink->ops = ops; xa_init_flags(&devlink->ports, XA_FLAGS_ALLOC); @@ -233,8 +228,6 @@ struct devlink *devlink_alloc_ns(const struct devlink_ops *ops, return devlink; -err_register_netdevice_notifier: - xa_erase(&devlinks, devlink->index); err_xa_alloc: kfree(devlink); return NULL; @@ -266,8 +259,6 @@ void devlink_free(struct devlink *devlink) xa_destroy(&devlink->params); xa_destroy(&devlink->ports); - WARN_ON_ONCE(unregister_netdevice_notifier(&devlink->netdevice_nb)); - xa_erase(&devlinks, devlink->index); devlink_put(devlink); @@ -303,6 +294,10 @@ static struct pernet_operations devlink_pernet_ops __net_initdata = { .pre_exit = devlink_pernet_pre_exit, }; +static struct notifier_block devlink_port_netdevice_nb __net_initdata = { + .notifier_call = devlink_port_netdevice_event, +}; + static int __init devlink_init(void) { int err; @@ -311,6 +306,9 @@ static int __init devlink_init(void) if (err) goto out; err = register_pernet_subsys(&devlink_pernet_ops); + if (err) + goto out; + err = register_netdevice_notifier(&devlink_port_netdevice_nb); out: WARN_ON(err); -- cgit v1.2.3-59-g8ed1b From d6352dae0903fe8beae4c007dc320e9e9f1fed45 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Mon, 15 May 2023 19:29:25 +0300 Subject: devlink: Fix crash with CONFIG_NET_NS=n '__net_initdata' becomes a no-op with CONFIG_NET_NS=y, but when this option is disabled it becomes '__initdata', which means the data can be freed after the initialization phase. This annotation is obviously incorrect for the devlink net device notifier block which is still registered after the initialization phase [1]. Fix this crash by removing the '__net_initdata' annotation. [1] general protection fault, probably for non-canonical address 0xcccccccccccccccc: 0000 [#1] PREEMPT SMP CPU: 3 PID: 117 Comm: (udev-worker) Not tainted 6.4.0-rc1-custom-gdf0acdc59b09 #64 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014 RIP: 0010:notifier_call_chain+0x58/0xc0 [...] Call Trace: dev_set_mac_address+0x85/0x120 dev_set_mac_address_user+0x30/0x50 do_setlink+0x219/0x1270 rtnl_setlink+0xf7/0x1a0 rtnetlink_rcv_msg+0x142/0x390 netlink_rcv_skb+0x58/0x100 netlink_unicast+0x188/0x270 netlink_sendmsg+0x214/0x470 __sys_sendto+0x12f/0x1a0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x38/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: e93c9378e33f ("devlink: change per-devlink netdev notifier to static one") Reported-by: Marek Szyprowski Closes: https://lore.kernel.org/netdev/600ddf9e-589a-2aa0-7b69-a438f833ca10@samsung.com/ Tested-by: Marek Szyprowski Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230515162925.1144416-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski --- net/devlink/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/devlink/core.c') diff --git a/net/devlink/core.c b/net/devlink/core.c index 0e58eee44bdb..c23ebabadc52 100644 --- a/net/devlink/core.c +++ b/net/devlink/core.c @@ -294,7 +294,7 @@ static struct pernet_operations devlink_pernet_ops __net_initdata = { .pre_exit = devlink_pernet_pre_exit, }; -static struct notifier_block devlink_port_netdevice_nb __net_initdata = { +static struct notifier_block devlink_port_netdevice_nb = { .notifier_call = devlink_port_netdevice_event, }; -- cgit v1.2.3-59-g8ed1b