BUG: KCSAN: data-race in console_unlock / console_unlock

write to 0xffffffff84181940 of 8 bytes by task 29690 on cpu 1:
 console_unlock+0x570/0xb30 kernel/printk/printk.c:2632
 vprintk_emit+0x125/0x3d0 kernel/printk/printk.c:2174
 vprintk_default+0x22/0x30 kernel/printk/printk.c:2185
 vprintk+0x15a/0x170 kernel/printk/printk_safe.c:392
 printk+0x62/0x87 kernel/printk/printk.c:2216
 __ext4_msg+0x103/0x110 fs/ext4/super.c:915
 handle_mount_opt fs/ext4/super.c:2200 [inline]
 parse_options+0x16ce/0x1870 fs/ext4/super.c:2439
 ext4_fill_super+0x1433/0x7ff0 fs/ext4/super.c:4296
 mount_bdev+0x1e8/0x290 fs/super.c:1368
 ext4_mount+0x2d/0x40 fs/ext4/super.c:6635
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:610
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1498
 do_new_mount fs/namespace.c:2915 [inline]
 path_mount+0x11ca/0x1d00 fs/namespace.c:3245
 do_mount fs/namespace.c:3258 [inline]
 __do_sys_mount fs/namespace.c:3466 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3443
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3443
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffffffff84181940 of 8 bytes by task 29661 on cpu 0:
 console_unlock+0x9f5/0xb30 kernel/printk/printk.c:2667
 do_con_write+0x5dc6/0x5e30 drivers/tty/vt/vt.c:270
 con_put_char+0x35/0x60 drivers/tty/vt/vt.c:3286
 tty_put_char+0x5f/0xa0 drivers/tty/tty_io.c:3173
 do_output_char+0x4ca/0x4f0 drivers/tty/n_tty.c:485
 process_output drivers/tty/n_tty.c:511 [inline]
 n_tty_write+0x7f8/0xaf0 drivers/tty/n_tty.c:2300
 do_tty_write drivers/tty/tty_io.c:1038 [inline]
 file_tty_write+0x409/0x660 drivers/tty/tty_io.c:1110
 tty_write+0x24/0x30 drivers/tty/tty_io.c:1131
 call_write_iter include/linux/fs.h:2157 [inline]
 do_iter_readv_writev+0x2cd/0x370 fs/read_write.c:729
 do_iter_write+0x192/0x5c0 fs/read_write.c:855
 vfs_writev fs/read_write.c:928 [inline]
 do_writev+0x1e0/0x400 fs/read_write.c:971
 __do_sys_writev fs/read_write.c:1044 [inline]
 __se_sys_writev fs/read_write.c:1041 [inline]
 __x64_sys_writev+0x41/0x50 fs/read_write.c:1041
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000000000652b -> 0x000000000000652c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 29661 Comm: syz-executor.2 Tainted: G        W         5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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