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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237c27760 of 8 bytes by task 11580 on cpu 0:
 bh_lru_install fs/buffer.c:1342 [inline]
 find_get_block_common+0x459/0x8a0 fs/buffer.c:1407
 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_mb_init_cache+0x2b8/0xc10 fs/ext4/mballoc.c:1430
 ext4_mb_init_group+0x42d/0x580 fs/ext4/mballoc.c:1657
 ext4_mb_good_group_nolock fs/ext4/mballoc.c:2833 [inline]
 ext4_mb_scan_group+0x5f4/0xf20 fs/ext4/mballoc.c:2970
 ext4_mb_scan_groups_linear fs/ext4/mballoc.c:1176 [inline]
 ext4_mb_scan_groups fs/ext4/mballoc.c:1208 [inline]
 ext4_mb_regular_allocator+0x696/0x16d0 fs/ext4/mballoc.c:3062
 ext4_mb_new_blocks+0x7db/0x1f50 fs/ext4/mballoc.c:6316
 ext4_new_meta_blocks+0x102/0x1f0 fs/ext4/balloc.c:750
 ext4_xattr_block_set+0x13ab/0x1a60 fs/ext4/xattr.c:2123
 ext4_xattr_set_handle+0xb26/0xf80 fs/ext4/xattr.c:2457
 __ext4_set_acl+0x313/0x380 fs/ext4/acl.c:217
 ext4_set_acl+0x2b8/0x3e0 fs/ext4/acl.c:259
 set_posix_acl fs/posix_acl.c:955 [inline]
 vfs_set_acl+0x615/0x7d0 fs/posix_acl.c:1134
 do_set_acl+0xa9/0x130 fs/posix_acl.c:1279
 do_setxattr fs/xattr.c:633 [inline]
 filename_setxattr+0x212/0x410 fs/xattr.c:664
 path_setxattrat+0x2be/0x310 fs/xattr.c:708
 __do_sys_setxattr fs/xattr.c:742 [inline]
 __se_sys_setxattr fs/xattr.c:738 [inline]
 __x64_sys_setxattr+0x6e/0x90 fs/xattr.c:738
 x64_sys_call+0x2ee2/0x3020 arch/x86/include/generated/asm/syscalls_64.h:189
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c27760 of 8 bytes by task 3314 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1548
 cpu_needs_drain mm/swap.c:787 [inline]
 __lru_add_drain_all+0x287/0x450 mm/swap.c:877
 lru_add_drain_all+0x10/0x20 mm/swap.c:893
 invalidate_bdev+0x47/0x70 block/bdev.c:101
 ext4_put_super+0x610/0x7b0 fs/ext4/super.c:1349
 generic_shutdown_super+0xee/0x220 fs/super.c:646
 kill_block_super+0x2a/0x70 fs/super.c:1725
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7484
 deactivate_locked_super+0x75/0x1c0 fs/super.c:476
 deactivate_super+0x97/0xa0 fs/super.c:509
 cleanup_mnt+0x2bb/0x330 fs/namespace.c:1312
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1319
 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+0x249/0x370 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffff88811a9d8068

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3314 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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