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BUG: KCSAN: data-race in console_unlock / console_unlock

write to 0xffffffff84548940 of 8 bytes by task 23863 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
 __show_regs+0x63/0x360 arch/x86/kernel/process_64.c:80
 show_regs_if_on_stack arch/x86/kernel/dumpstack.c:173 [inline]
 show_trace_log_lvl+0x548/0x600 arch/x86/kernel/dumpstack.c:298
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x137/0x19d lib/dump_stack.c:120
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail+0x23c/0x250 lib/fault-inject.c:146
 should_fail_usercopy+0x16/0x20 lib/fault-inject-usercopy.c:37
 strncpy_from_user+0x21/0x250 lib/strncpy_from_user.c:118
 getname_flags+0xb8/0x3d0 fs/namei.c:149
 user_path_at_empty+0x28/0x50 fs/namei.c:2734
 user_path_at include/linux/namei.h:60 [inline]
 do_mount fs/namespace.c:3245 [inline]
 __do_sys_mount fs/namespace.c:3456 [inline]
 __se_sys_mount+0x209/0x2e0 fs/namespace.c:3433
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3433
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffffffff84548940 of 8 bytes by task 23871 on cpu 0:
 console_unlock+0x9f5/0xb30 kernel/printk/printk.c:2667
 con_get_trans_old+0x24f/0x2b0 drivers/tty/vt/consolemap.c:353
 vt_io_ioctl drivers/tty/vt/vt_ioctl.c:526 [inline]
 vt_ioctl+0x82a/0x1ed0 drivers/tty/vt/vt_ioctl.c:717
 tty_ioctl+0xa24/0x1120 drivers/tty/tty_io.c:2805
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:1055
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 23871 Comm: syz-executor.0 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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