syzbot

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BUG: KCSAN: data-race in __ip_append_data / __netdev_update_features

write to 0xffff8881193b00b8 of 8 bytes by task 31665 on cpu 1:
 __netdev_update_features+0x12a9/0x1500 net/core/dev.c:11073
 netdev_change_features+0x27/0x110 net/core/dev.c:11106
 netdev_compute_master_upper_features+0x5ed/0x610 net/core/dev.c:12861
 __bond_release_one+0x66e/0x9f0 drivers/net/bonding/bond_main.c:2481
 bond_release+0x21/0x30 drivers/net/bonding/bond_main.c:2546
 do_set_master+0x227/0x460 net/core/rtnetlink.c:2947
 do_setlink+0x97b/0x2940 net/core/rtnetlink.c:3165
 rtnl_group_changelink net/core/rtnetlink.c:3790 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3944 [inline]
 rtnl_newlink+0xeee/0x1330 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2550
 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:6985
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5c0/0x690 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x5c8/0x6f0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0x5af/0x600 net/socket.c:2592
 ___sys_sendmsg+0x195/0x1e0 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2681
 x64_sys_call+0x194c/0x3020 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881193b00b8 of 8 bytes by task 31666 on cpu 0:
 __ip_append_data+0x2d1/0x2460 net/ipv4/ip_output.c:1002
 ip_make_skb+0x150/0x2d0 net/ipv4/ip_output.c:1574
 udp_sendmsg+0x10e3/0x1590 net/ipv4/udp.c:1480
 inet_sendmsg+0xac/0xd0 net/ipv4/af_inet.c:859
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0x53a/0x600 net/socket.c:2592
 ___sys_sendmsg+0x195/0x1e0 net/socket.c:2646
 __sys_sendmmsg+0x185/0x320 net/socket.c:2735
 __do_sys_sendmmsg net/socket.c:2762 [inline]
 __se_sys_sendmmsg net/socket.c:2759 [inline]
 __x64_sys_sendmmsg+0x57/0x70 net/socket.c:2759
 x64_sys_call+0x27aa/0x3020 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000e00e5fddcbe9 -> 0x0000e2001fe0c388

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 31666 Comm: syz.0.5244 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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