EXT4-fs (loop2): unmounting filesystem 76b65be2-f6da-4727-8c75-0525a5b65a09.
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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237d277a0 of 8 bytes by task 17708 on cpu 1:
 bh_lru_install fs/buffer.c:1235 [inline]
 find_get_block_common+0x459/0x8a0 fs/buffer.c:1300
 bdev_getblk+0x4d/0x3f0 include/linux/gfp.h:-1
 __getblk include/linux/buffer_head.h:380 [inline]
 sb_getblk include/linux/buffer_head.h:386 [inline]
 ext4_read_block_bitmap_nowait+0x168/0x680 fs/ext4/balloc.c:488
 ext4_read_block_bitmap+0x1e/0x70 fs/ext4/balloc.c:600
 ext4_mb_mark_context+0x9d/0x900 fs/ext4/mballoc.c:4105
 ext4_mb_clear_bb fs/ext4/mballoc.c:6602 [inline]
 ext4_free_blocks+0x80e/0x14a0 fs/ext4/mballoc.c:6788
 ext4_clear_blocks+0x2a2/0x2c0 fs/ext4/indirect.c:888
 ext4_free_data+0x110/0x2a0 fs/ext4/indirect.c:949
 ext4_free_branches+0x62/0x410 fs/ext4/indirect.c:1108
 ext4_ind_remove_space+0xed3/0x1310 fs/ext4/indirect.c:1397
 ext4_punch_hole+0x545/0x7a0 fs/ext4/inode.c:4426
 ext4_fallocate+0x2d7/0x2f0 fs/ext4/extents.c:4904
 vfs_fallocate+0x3b6/0x450 fs/open.c:338
 ioctl_preallocate fs/ioctl.c:289 [inline]
 file_ioctl+0x4e3/0x5c0 fs/ioctl.c:-1
 do_vfs_ioctl+0x7c9/0xe70 fs/ioctl.c:576
 __do_sys_ioctl fs/ioctl.c:595 [inline]
 __se_sys_ioctl+0x82/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x1563/0x3020 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d277a0 of 8 bytes by task 17142 on cpu 0:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1441
 smp_call_function_many_cond+0x2c1/0xc30 kernel/smp.c:821
 on_each_cpu_cond_mask+0x3c/0x80 kernel/smp.c:1043
 on_each_cpu_cond include/linux/smp.h:106 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1450
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x9a/0x1a0 block/bdev.c:720
 blkdev_put_whole block/bdev.c:727 [inline]
 bdev_release+0x2bf/0x3d0 block/bdev.c:1152
 blkdev_release+0x15/0x20 block/fops.c:705
 __fput+0x29b/0x630 fs/file_table.c:510
 ____fput+0x1c/0x30 fs/file_table.c:538
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x1f4/0x6f0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x232/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff88811a5f3a28 -> 0xffff88811a579270

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 17142 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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