syzbot

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BUG: KCSAN: data-race in register_netdevice / type_show

write to 0xffff88816765a4e0 of 1 bytes by task 14992 on cpu 1:
 register_netdevice+0xc49/0x10b0 net/core/dev.c:10338
 slip_open+0x843/0x940 drivers/net/slip/slip.c:833
 tty_ldisc_open drivers/tty/tty_ldisc.c:449 [inline]
 tty_set_ldisc+0x27f/0x580 drivers/tty/tty_ldisc.c:579
 tiocsetd drivers/tty/tty_io.c:2455 [inline]
 tty_ioctl+0xf7a/0x1130 drivers/tty/tty_io.c:2741
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:860
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88816765a4e0 of 1 bytes by task 21246 on cpu 0:
 dev_isalive net/core/net-sysfs.c:37 [inline]
 netdev_show net/core/net-sysfs.c:49 [inline]
 type_show+0x24/0x90 net/core/net-sysfs.c:111
 dev_attr_show+0x35/0x90 drivers/base/core.c:2095
 sysfs_kf_seq_show+0x175/0x290 fs/sysfs/file.c:59
 kernfs_seq_show+0x74/0x80 fs/kernfs/file.c:168
 seq_read_iter+0x2e1/0x930 fs/seq_file.c:230
 kernfs_fop_read_iter+0xd9/0x320 fs/kernfs/file.c:241
 call_read_iter include/linux/fs.h:2156 [inline]
 new_sync_read fs/read_write.c:400 [inline]
 vfs_read+0x66c/0x750 fs/read_write.c:481
 ksys_read+0xd9/0x190 fs/read_write.c:619
 __do_sys_read fs/read_write.c:629 [inline]
 __se_sys_read fs/read_write.c:627 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:627
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 21246 Comm: udevd Tainted: G        W         5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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