kernel/linux.git/net/8021q/vlan_dev.c, branch v6.1.174

net: vlan: don't propagate flags on open

2025-04-25T08:43:31+00:00

[ Upstream commit 27b918007d96402aba10ed52a6af8015230f1793 ] With the device instance lock, there is now a possibility of a deadlock: [ 1.211455] ============================================ [ 1.211571] WARNING: possible recursive locking detected [ 1.211687] 6.14.0-rc5-01215-g032756b4ca7a-dirty #5 Not tainted [ 1.211823] -------------------------------------------- [ 1.211936] ip/184 is trying to acquire lock: [ 1.212032] ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_set_allmulti+0x4e/0xb0 [ 1.212207] [ 1.212207] but task is already holding lock: [ 1.212332] ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_open+0x50/0xb0 [ 1.212487] [ 1.212487] other info that might help us debug this: [ 1.212626] Possible unsafe locking scenario: [ 1.212626] [ 1.212751] CPU0 [ 1.212815] ---- [ 1.212871] lock(&dev->lock); [ 1.212944] lock(&dev->lock); [ 1.213016] [ 1.213016] *** DEADLOCK *** [ 1.213016] [ 1.213143] May be due to missing lock nesting notation [ 1.213143] [ 1.213294] 3 locks held by ip/184: [ 1.213371] #0: ffffffff838b53e0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock+0x1b/0xa0 [ 1.213543] #1: ffffffff84e5fc70 (&net->rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock+0x37/0xa0 [ 1.213727] #2: ffff8881024a4c30 (&dev->lock){+.+.}-{4:4}, at: dev_open+0x50/0xb0 [ 1.213895] [ 1.213895] stack backtrace: [ 1.213991] CPU: 0 UID: 0 PID: 184 Comm: ip Not tainted 6.14.0-rc5-01215-g032756b4ca7a-dirty #5 [ 1.213993] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014 [ 1.213994] Call Trace: [ 1.213995] [ 1.213996] dump_stack_lvl+0x8e/0xd0 [ 1.214000] print_deadlock_bug+0x28b/0x2a0 [ 1.214020] lock_acquire+0xea/0x2a0 [ 1.214027] __mutex_lock+0xbf/0xd40 [ 1.214038] dev_set_allmulti+0x4e/0xb0 # real_dev->flags & IFF_ALLMULTI [ 1.214040] vlan_dev_open+0xa5/0x170 # ndo_open on vlandev [ 1.214042] __dev_open+0x145/0x270 [ 1.214046] __dev_change_flags+0xb0/0x1e0 [ 1.214051] netif_change_flags+0x22/0x60 # IFF_UP vlandev [ 1.214053] dev_change_flags+0x61/0xb0 # for each device in group from dev->vlan_info [ 1.214055] vlan_device_event+0x766/0x7c0 # on netdevsim0 [ 1.214058] notifier_call_chain+0x78/0x120 [ 1.214062] netif_open+0x6d/0x90 [ 1.214064] dev_open+0x5b/0xb0 # locks netdevsim0 [ 1.214066] bond_enslave+0x64c/0x1230 [ 1.214075] do_set_master+0x175/0x1e0 # on netdevsim0 [ 1.214077] do_setlink+0x516/0x13b0 [ 1.214094] rtnl_newlink+0xaba/0xb80 [ 1.214132] rtnetlink_rcv_msg+0x440/0x490 [ 1.214144] netlink_rcv_skb+0xeb/0x120 [ 1.214150] netlink_unicast+0x1f9/0x320 [ 1.214153] netlink_sendmsg+0x346/0x3f0 [ 1.214157] __sock_sendmsg+0x86/0xb0 [ 1.214160] ____sys_sendmsg+0x1c8/0x220 [ 1.214164] ___sys_sendmsg+0x28f/0x2d0 [ 1.214179] __x64_sys_sendmsg+0xef/0x140 [ 1.214184] do_syscall_64+0xec/0x1d0 [ 1.214190] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 1.214191] RIP: 0033:0x7f2d1b4a7e56 Device setup: netdevsim0 (down) ^ ^ bond netdevsim1.100@netdevsim1 allmulticast=on (down) When we enslave the lower device (netdevsim0) which has a vlan, we propagate vlan's allmuti/promisc flags during ndo_open. This causes (re)locking on of the real_dev. Propagate allmulti/promisc on flags change, not on the open. There is a slight semantics change that vlans that are down now propagate the flags, but this seems unlikely to result in the real issues. Reproducer: echo 0 1 > /sys/bus/netdevsim/new_device dev_path=$(ls -d /sys/bus/netdevsim/devices/netdevsim0/net/*) dev=$(echo $dev_path | rev | cut -d/ -f1 | rev) ip link set dev $dev name netdevsim0 ip link set dev netdevsim0 up ip link add link netdevsim0 name netdevsim0.100 type vlan id 100 ip link set dev netdevsim0.100 allmulticast on down ip link add name bond1 type bond mode 802.3ad ip link set dev netdevsim0 down ip link set dev netdevsim0 master bond1 ip link set dev bond1 up ip link show Reported-by: syzbot+b0c03d76056ef6cd12a6@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/Z9CfXjLMKn6VLG5d@mini-arch/T/#m15ba130f53227c883e79fb969687d69d670337a0 Signed-off-by: Stanislav Fomichev Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250313100657.2287455-1-sdf@fomichev.me Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

vlan: fix a potential uninit-value in vlan_dev_hard_start_xmit()

2023-05-24T16:32:47+00:00

[ Upstream commit dacab578c7c6cd06c50c89dfa36b0e0f10decd4e ] syzbot triggered the following splat [1], sending an empty message through pppoe_sendmsg(). When VLAN_FLAG_REORDER_HDR flag is set, vlan_dev_hard_header() does not push extra bytes for the VLAN header, because vlan is offloaded. Unfortunately vlan_dev_hard_start_xmit() first reads veth->h_vlan_proto before testing (vlan->flags & VLAN_FLAG_REORDER_HDR). We need to swap the two conditions. [1] BUG: KMSAN: uninit-value in vlan_dev_hard_start_xmit+0x171/0x7f0 net/8021q/vlan_dev.c:111 vlan_dev_hard_start_xmit+0x171/0x7f0 net/8021q/vlan_dev.c:111 __netdev_start_xmit include/linux/netdevice.h:4883 [inline] netdev_start_xmit include/linux/netdevice.h:4897 [inline] xmit_one net/core/dev.c:3580 [inline] dev_hard_start_xmit+0x253/0xa20 net/core/dev.c:3596 __dev_queue_xmit+0x3c7f/0x5ac0 net/core/dev.c:4246 dev_queue_xmit include/linux/netdevice.h:3053 [inline] pppoe_sendmsg+0xa93/0xb80 drivers/net/ppp/pppoe.c:900 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0xa24/0xe40 net/socket.c:2501 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555 __sys_sendmmsg+0x411/0xa50 net/socket.c:2641 __do_sys_sendmmsg net/socket.c:2670 [inline] __se_sys_sendmmsg net/socket.c:2667 [inline] __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2667 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:774 slab_alloc_node mm/slub.c:3452 [inline] kmem_cache_alloc_node+0x543/0xab0 mm/slub.c:3497 kmalloc_reserve+0x148/0x470 net/core/skbuff.c:520 __alloc_skb+0x3a7/0x850 net/core/skbuff.c:606 alloc_skb include/linux/skbuff.h:1277 [inline] sock_wmalloc+0xfe/0x1a0 net/core/sock.c:2583 pppoe_sendmsg+0x3af/0xb80 drivers/net/ppp/pppoe.c:867 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] ____sys_sendmsg+0xa24/0xe40 net/socket.c:2501 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2555 __sys_sendmmsg+0x411/0xa50 net/socket.c:2641 __do_sys_sendmmsg net/socket.c:2670 [inline] __se_sys_sendmmsg net/socket.c:2667 [inline] __x64_sys_sendmmsg+0xbc/0x120 net/socket.c:2667 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd CPU: 0 PID: 29770 Comm: syz-executor.0 Not tainted 6.3.0-rc6-syzkaller-gc478e5b17829 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

vlan: partially enable SIOCSHWTSTAMP in container

2023-05-11T14:03:18+00:00

[ Upstream commit 731b73dba359e3ff00517c13aa0daa82b34ff466 ] Setting timestamp filter was explicitly disabled on vlan devices in containers because it might affect other processes on the host. But it's absolutely legit in case when real device is in the same namespace. Fixes: 873017af7784 ("vlan: disable SIOCSHWTSTAMP in container") Signed-off-by: Vadim Fedorenko Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

vlan: move from strlcpy with unused retval to strscpy

2022-08-23T00:55:48+00:00

Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang Link: https://lore.kernel.org/r/20220818210204.8275-1-wsa+renesas@sang-engineering.com Signed-off-by: Jakub Kicinski

vlan: adopt u64_stats_t

2022-06-10T04:53:09+00:00

As explained in commit 316580b69d0a ("u64_stats: provide u64_stats_t type") we should use u64_stats_t and related accessors to avoid load/store tearing. Add READ_ONCE() when reading rx_errors & tx_dropped. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

net: rename reference+tracking helpers

2022-06-10T04:52:55+00:00

Netdev reference helpers have a dev_ prefix for historic reasons. Renaming the old helpers would be too much churn but we can rename the tracking ones which are relatively recent and should be the default for new code. Rename: dev_hold_track() -> netdev_hold() dev_put_track() -> netdev_put() dev_replace_track() -> netdev_ref_replace() Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: add netif_inherit_tso_max()

2022-05-06T11:07:56+00:00

To make later patches smaller create a helper for inheriting the TSO limitations of a lower device. The TSO in the name is not an accident, subsequent patches will replace GSO with TSO in more names. Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller

Revert "vlan: move dev_put into vlan_dev_uninit"

2022-02-23T23:21:13+00:00

This reverts commit d6ff94afd90b0ce8d1715f8ef77d4347d7a7f2c0. Since commit faab39f63c1f ("net: allow out-of-order netdev unregistration") fixed the issue in a better way, this patch is to revert the previous fix, as it might bring back the old problem fixed by commit 563bcbae3ba2 ("net: vlan: fix a UAF in vlan_dev_real_dev()"). Signed-off-by: Xin Long Link: https://lore.kernel.org/r/563c0a6e48510ccbff9ef4715de37209695e9fc4.1645592097.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski

vlan: move dev_put into vlan_dev_uninit

2022-02-09T13:33:39+00:00

Shuang Li reported an QinQ issue by simply doing: # ip link add dummy0 type dummy # ip link add link dummy0 name dummy0.1 type vlan id 1 # ip link add link dummy0.1 name dummy0.1.2 type vlan id 2 # rmmod 8021q unregister_netdevice: waiting for dummy0.1 to become free. Usage count = 1 When rmmods 8021q, all vlan devs are deleted from their real_dev's vlan grp and added into list_kill by unregister_vlan_dev(). dummy0.1 is unregistered before dummy0.1.2, as it's using for_each_netdev() in __rtnl_kill_links(). When unregisters dummy0.1, dummy0.1.2 is not unregistered in the event of NETDEV_UNREGISTER, as it's been deleted from dummy0.1's vlan grp. However, due to dummy0.1.2 still holding dummy0.1, dummy0.1 will keep waiting in netdev_wait_allrefs(), while dummy0.1.2 will never get unregistered and release dummy0.1, as it delays dev_put until calling dev->priv_destructor, vlan_dev_free(). This issue was introduced by Commit 563bcbae3ba2 ("net: vlan: fix a UAF in vlan_dev_real_dev()"), and this patch is to fix it by moving dev_put() into vlan_dev_uninit(), which is called after NETDEV_UNREGISTER event but before netdev_wait_allrefs(). Fixes: 563bcbae3ba2 ("net: vlan: fix a UAF in vlan_dev_real_dev()") Reported-by: Shuang Li Signed-off-by: Xin Long Signed-off-by: David S. Miller

vlan: introduce vlan_dev_free_egress_priority

2022-02-09T13:33:39+00:00

This patch is to introduce vlan_dev_free_egress_priority() to free egress priority for vlan dev, and keep vlan_dev_uninit() static as .ndo_uninit. It makes the code more clear and safer when adding new code in vlan_dev_uninit() in the future. Signed-off-by: Xin Long Signed-off-by: David S. Miller