syzbot

EXT4-fs (loop5): unmounting filesystem 00000000-0000-0000-0000-000000000000.
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BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237d26fd0 of 8 bytes by task 528 on cpu 1:
 bh_lru_install fs/buffer.c:1345 [inline]
 find_get_block_common+0x4f0/0x960 fs/buffer.c:1410
 __find_get_block_nonatomic fs/buffer.c:1429 [inline]
 bdev_getblk+0x83/0x3b0 fs/buffer.c:1453
 __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+0x240/0xba0 fs/ext4/mballoc.c:1406
 ext4_mb_init_group+0x25b/0x3f0 fs/ext4/mballoc.c:1612
 ext4_mb_load_buddy_gfp+0x72a/0x790 fs/ext4/mballoc.c:1682
 ext4_mb_clear_bb fs/ext4/mballoc.c:6568 [inline]
 ext4_free_blocks+0x761/0x1480 fs/ext4/mballoc.c:6770
 ext4_remove_blocks fs/ext4/extents.c:2551 [inline]
 ext4_ext_rm_leaf fs/ext4/extents.c:2716 [inline]
 ext4_ext_remove_space+0x177b/0x2900 fs/ext4/extents.c:2965
 ext4_ext_truncate+0xc7/0x170 fs/ext4/extents.c:4484
 ext4_truncate+0x70d/0xae0 fs/ext4/inode.c:4614
 ext4_process_orphan+0x110/0x1c0 fs/ext4/orphan.c:335
 ext4_orphan_cleanup+0x6a8/0xa00 fs/ext4/orphan.c:470
 __ext4_fill_super fs/ext4/super.c:5617 [inline]
 ext4_fill_super+0x3483/0x3810 fs/ext4/super.c:5736
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1691
 get_tree_bdev+0x1f/0x30 fs/super.c:1714
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5768
 vfs_get_tree+0x57/0x1d0 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount+0x24d/0x660 fs/namespace.c:3727
 path_mount+0x4a5/0xb70 fs/namespace.c:4037
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4215
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4215
 x64_sys_call+0x2b51/0x3000 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237d26fd0 of 8 bytes by task 17874 on cpu 0:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1551
 smp_call_function_many_cond+0x2a9/0xc60 kernel/smp.c:821
 on_each_cpu_cond_mask+0x3c/0x80 kernel/smp.c:1043
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1560
 invalidate_bdev+0x42/0x70 block/bdev.c:100
 ext4_put_super+0x624/0x7d0 fs/ext4/super.c:1348
 generic_shutdown_super+0xe6/0x210 fs/super.c:642
 kill_block_super+0x2a/0x70 fs/super.c:1722
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7403
 deactivate_locked_super+0x75/0x1c0 fs/super.c:473
 deactivate_super+0x97/0xa0 fs/super.c:506
 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1327
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1334
 task_work_run+0x131/0x1a0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xed/0x110 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888122842f08 -> 0xffff88811a262d68

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 17874 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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