kernel/net/8021q/vlan_dev.c, branch linux-rolling-stable

net: vlan: don't propagate flags on open

2025-03-20T08:57:37Z

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

net: move misc netdev_lock flavors to a separate header

2025-03-08T17:06:50Z

Move the more esoteric helpers for netdev instance lock to a dedicated header. This avoids growing netdevice.h to infinity and makes rebuilding the kernel much faster (after touching the header with the helpers). The main netdev_lock() / netdev_unlock() functions are used in static inlines in netdevice.h and will probably be used most commonly, so keep them in netdevice.h. Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: hold netdev instance lock during ioctl operations

2025-03-06T20:59:44Z

Convert all ndo_eth_ioctl invocations to dev_eth_ioctl which does the locking. Reflow some of the dev_siocxxx to drop else clause. Cc: Saeed Mahameed Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250305163732.2766420-8-sdf@fomichev.me Signed-off-by: Jakub Kicinski

netpoll: remove ndo_netpoll_setup() second argument

2024-10-23T11:31:32Z

npinfo is not used in any of the ndo_netpoll_setup() methods. Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Link: https://patch.msgid.link/20241018052108.2610827-1-edumazet@google.com Signed-off-by: Paolo Abeni

netdev_features: remove NETIF_F_ALL_FCOE

2024-09-03T09:36:43Z

NETIF_F_ALL_FCOE is used only in vlan_dev.c, 2 times. Now that it's only 2 bits, open-code it and remove the definition from netdev_features.h. Suggested-by: Jakub Kicinski Signed-off-by: Alexander Lobakin Signed-off-by: Paolo Abeni

netdev_features: convert NETIF_F_FCOE_MTU to dev->fcoe_mtu

2024-09-03T09:36:43Z

Ability to handle maximum FCoE frames of 2158 bytes can never be changed and thus more of an attribute, not a toggleable feature. Move it from netdev_features_t to "cold" priv flags (bitfield bool) and free yet another feature bit. Signed-off-by: Alexander Lobakin Signed-off-by: Paolo Abeni

netdev_features: convert NETIF_F_LLTX to dev->lltx

2024-09-03T09:36:43Z

NETIF_F_LLTX can't be changed via Ethtool and is not a feature, rather an attribute, very similar to IFF_NO_QUEUE (and hot). Free one netdev_features_t bit and make it a "hot" private flag. Signed-off-by: Alexander Lobakin Signed-off-by: Paolo Abeni

net: Add struct kernel_ethtool_ts_info

2024-07-15T15:02:26Z

In prevision to add new UAPI for hwtstamp we will be limited to the struct ethtool_ts_info that is currently passed in fixed binary format through the ETHTOOL_GET_TS_INFO ethtool ioctl. It would be good if new kernel code already started operating on an extensible kernel variant of that structure, similar in concept to struct kernel_hwtstamp_config vs struct hwtstamp_config. Since struct ethtool_ts_info is in include/uapi/linux/ethtool.h, here we introduce the kernel-only structure in include/linux/ethtool.h. The manual copy is then made in the function called by ETHTOOL_GET_TS_INFO. Acked-by: Shannon Nelson Acked-by: Alexandra Winter Signed-off-by: Kory Maincent Link: https://patch.msgid.link/20240709-feature_ptp_netnext-v17-6-b5317f50df2a@bootlin.com Signed-off-by: Jakub Kicinski

net: annotate writes on dev->mtu from ndo_change_mtu()

2024-05-07T23:19:14Z

Simon reported that ndo_change_mtu() methods were never updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted in commit 501a90c94510 ("inet: protect against too small mtu values.") We read dev->mtu without holding RTNL in many places, with READ_ONCE() annotations. It is time to take care of ndo_change_mtu() methods to use corresponding WRITE_ONCE() Signed-off-by: Eric Dumazet Reported-by: Simon Horman Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/ Reviewed-by: Jacob Keller Reviewed-by: Sabrina Dubroca Reviewed-by: Simon Horman Acked-by: Shannon Nelson Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com Signed-off-by: Jakub Kicinski

rtnetlink: prepare nla_put_iflink() to run under RCU

2024-02-26T11:46:12Z

We want to be able to run rtnl_fill_ifinfo() under RCU protection instead of RTNL in the future. This patch prepares dev_get_iflink() and nla_put_iflink() to run either with RTNL or RCU held. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller