syzbot

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BUG: KCSAN: data-race in has_bh_in_lru / invalidate_bh_lru

write to 0xffff888237c2b990 of 8 bytes by task 5202 on cpu 0:
 __invalidate_bh_lrus fs/buffer.c:1488 [inline]
 invalidate_bh_lru+0x8b/0xf0 fs/buffer.c:1500
 csd_do_func kernel/smp.c:133 [inline]
 smp_call_function_many_cond+0x6bd/0xc50 kernel/smp.c:846
 on_each_cpu_cond_mask+0x3c/0x90 kernel/smp.c:1023
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1519
 kill_bdev block/bdev.c:84 [inline]
 set_blocksize+0x260/0x290 block/bdev.c:161
 sb_set_blocksize+0x2d/0xb0 block/bdev.c:170
 ext4_load_super fs/ext4/super.c:5094 [inline]
 __ext4_fill_super fs/ext4/super.c:5222 [inline]
 ext4_fill_super+0xad5/0x39d0 fs/ext4/super.c:5699
 get_tree_bdev+0x253/0x2e0 fs/super.c:1614
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5731
 vfs_get_tree+0x56/0x1d0 fs/super.c:1779
 do_new_mount+0x227/0x690 fs/namespace.c:3352
 path_mount+0x49b/0xb30 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount+0x27f/0x2d0 fs/namespace.c:3875
 __x64_sys_mount+0x67/0x80 fs/namespace.c:3875
 x64_sys_call+0x2591/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c2b990 of 8 bytes by task 3096 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1510
 smp_call_function_many_cond+0x2f6/0xc50 kernel/smp.c:808
 on_each_cpu_cond_mask+0x3c/0x90 kernel/smp.c:1023
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1519
 invalidate_bdev+0x4f/0x80 block/bdev.c:94
 ext4_put_super+0x51b/0x7e0 fs/ext4/super.c:1361
 generic_shutdown_super+0xde/0x210 fs/super.c:641
 kill_block_super+0x2a/0x70 fs/super.c:1675
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7327
 deactivate_locked_super+0x7d/0x1c0 fs/super.c:472
 deactivate_super+0x9f/0xb0 fs/super.c:505
 cleanup_mnt+0x272/0x2e0 fs/namespace.c:1267
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1274
 task_work_run+0x13a/0x1a0 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
 do_syscall_64+0xda/0x1d0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888106ee23a8 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3096 Comm: syz-executor.1 Not tainted 6.9.0-rc6-syzkaller-00005-gb947cc5bf6d7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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EXT4-fs (loop1): unmounting filesystem 00000000-0000-0000-0000-000000000000.