syzbot

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BUG: KCSAN: data-race in __netdev_update_features / netif_skb_features

write to 0xffff888118c800b8 of 8 bytes by task 24903 on cpu 0:
 __netdev_update_features+0xf21/0x1170 net/core/dev.c:10759
 netdev_update_features+0x29/0x90 net/core/dev.c:10775
 br_del_if+0x1be/0x1e0 net/bridge/br_if.c:751
 br_del_slave+0x24/0x30 net/bridge/br_device.c:382
 do_set_master+0x227/0x460 net/core/rtnetlink.c:2930
 do_setlink+0xa43/0x2810 net/core/rtnetlink.c:3148
 rtnl_group_changelink net/core/rtnetlink.c:3773 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3927 [inline]
 rtnl_newlink+0xd8b/0x12d0 net/core/rtnetlink.c:4055
 rtnetlink_rcv_msg+0x5fb/0x6d0 net/core/rtnetlink.c:6944
 netlink_rcv_skb+0x120/0x220 net/netlink/af_netlink.c:2552
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6971
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5a5/0x680 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x58b/0x6b0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x142/0x180 net/socket.c:727
 ____sys_sendmsg+0x31e/0x4e0 net/socket.c:2566
 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2620
 __sys_sendmsg net/socket.c:2652 [inline]
 __do_sys_sendmsg net/socket.c:2657 [inline]
 __se_sys_sendmsg net/socket.c:2655 [inline]
 __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2655
 x64_sys_call+0x2999/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888118c800b8 of 8 bytes by task 3407 on cpu 1:
 netif_skb_features+0x39/0x730 net/core/dev.c:3791
 validate_xmit_skb+0x67/0x910 net/core/dev.c:3938
 __dev_queue_xmit+0xd19/0x1fb0 net/core/dev.c:4705
 dev_queue_xmit include/linux/netdevice.h:3355 [inline]
 neigh_hh_output include/net/neighbour.h:523 [inline]
 neigh_output include/net/neighbour.h:537 [inline]
 ip6_finish_output2+0xa3c/0xd30 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
 ip6_finish_output+0x3a2/0x530 net/ipv6/ip6_output.c:226
 NF_HOOK_COND include/linux/netfilter.h:306 [inline]
 ip6_output+0xfd/0x240 net/ipv6/ip6_output.c:247
 dst_output include/net/dst.h:459 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 mld_sendpack+0x427/0x6e0 net/ipv6/mcast.c:1868
 mld_send_cr net/ipv6/mcast.c:2169 [inline]
 mld_ifc_work+0x55c/0x840 net/ipv6/mcast.c:2702
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000200fffdd48e9 -> 0x0000200fffff48e9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3407 Comm: kworker/1:5 Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: mld mld_ifc_work
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