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BUG: KCSAN: data-race in console_flush_all / console_flush_all

write to 0xffffffff86a1d388 of 8 bytes by task 4751 on cpu 1:
 console_emit_next_record kernel/printk/printk.c:3099 [inline]
 console_flush_all+0x35a/0x730 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xa1/0x330 kernel/printk/printk.c:3325
 vprintk_emit+0x388/0x650 kernel/printk/printk.c:2450
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2465
 vprintk+0x1d/0x30 kernel/printk/printk_safe.c:82
 _printk+0x79/0xa0 kernel/printk/printk.c:2475
 isofs_fill_super+0x125e/0x1280 fs/isofs/inode.c:661
 get_tree_bdev_flags+0x28e/0x300 fs/super.c:1636
 get_tree_bdev+0x1f/0x30 fs/super.c:1659
 isofs_get_tree+0x1c/0x30 fs/isofs/inode.c:1523
 vfs_get_tree+0x54/0x1d0 fs/super.c:1759
 do_new_mount+0x207/0x680 fs/namespace.c:3884
 path_mount+0x4a4/0xb20 fs/namespace.c:4211
 do_mount fs/namespace.c:4224 [inline]
 __do_sys_mount fs/namespace.c:4435 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4412
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4412
 x64_sys_call+0xd36/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff86a1d388 of 8 bytes by task 4748 on cpu 0:
 console_flush_all+0x563/0x730 kernel/printk/printk.c:3227
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xa1/0x330 kernel/printk/printk.c:3325
 do_con_write+0x25c3/0x2630 drivers/tty/vt/vt.c:-1
 con_write+0x24/0x40 drivers/tty/vt/vt.c:3432
 process_output_block drivers/tty/n_tty.c:561 [inline]
 n_tty_write+0x7d8/0xb10 drivers/tty/n_tty.c:2377
 iterate_tty_write drivers/tty/tty_io.c:1015 [inline]
 file_tty_write+0x389/0x670 drivers/tty/tty_io.c:1090
 tty_write+0x25/0x30 drivers/tty/tty_io.c:1111
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x49d/0x8d0 fs/read_write.c:684
 ksys_write+0xda/0x1a0 fs/read_write.c:736
 __do_sys_write fs/read_write.c:747 [inline]
 __se_sys_write fs/read_write.c:744 [inline]
 __x64_sys_write+0x40/0x50 fs/read_write.c:744
 x64_sys_call+0x2cdd/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000a97 -> 0x0000000000000a98

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4748 Comm: syz.4.445 Not tainted 6.15.0-rc4-syzkaller-00189-g2bfcee565c3a #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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