syzbot

EXT4-fs (loop8): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in find_get_block_common / has_bh_in_lru

read-write to 0xffff888237d27760 of 8 bytes by task 9837 on cpu 1:
 bh_lru_install fs/buffer.c:1343 [inline]
 find_get_block_common+0x459/0x8a0 fs/buffer.c:1408
 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_get_inode_loc+0x303/0x930 fs/ext4/inode.c:4787
 ext4_get_inode_loc+0x66/0xe0 fs/ext4/inode.c:4915
 ext4_xattr_ibody_get+0x92/0x2d0 fs/ext4/xattr.c:648
 ext4_xattr_get+0xdc/0x470 fs/ext4/xattr.c:709
 ext4_xattr_security_get+0x32/0x40 fs/ext4/xattr_security.c:20
 __vfs_getxattr+0x2ad/0x2c0 fs/xattr.c:423
 get_vfs_caps_from_disk+0x9e/0x360 security/commoncap.c:694
 get_file_caps security/commoncap.c:785 [inline]
 cap_bprm_creds_from_file+0x1a2/0xcf0 security/commoncap.c:931
 security_bprm_creds_from_file+0x3c/0x70 security/security.c:777
 bprm_creds_from_file fs/exec.c:1589 [inline]
 begin_new_exec+0x1f6/0x1270 fs/exec.c:1097
 load_elf_binary+0x62b/0x1a20 fs/binfmt_elf.c:1010
 search_binary_handler fs/exec.c:1664 [inline]
 exec_binprm fs/exec.c:1696 [inline]
 bprm_execve+0x476/0x9c0 fs/exec.c:1748
 do_execveat_common+0x6b7/0x720 fs/exec.c:1846
 __do_sys_execve fs/exec.c:1930 [inline]
 __se_sys_execve fs/exec.c:1924 [inline]
 __x64_sys_execve+0x5f/0x80 fs/exec.c:1924
 x64_sys_call+0x2752/0x3020 arch/x86/include/generated/asm/syscalls_64.h:60
 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 0xffff888237d27760 of 8 bytes by task 8951 on cpu 0:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1549
 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:1558
 kill_bdev block/bdev.c:90 [inline]
 blkdev_flush_mapping+0x9a/0x1a0 block/bdev.c:728
 blkdev_put_whole block/bdev.c:735 [inline]
 bdev_release+0x2bf/0x3d0 block/bdev.c:1160
 blkdev_release+0x15/0x20 block/fops.c:706
 __fput+0x29b/0x650 fs/file_table.c:469
 ____fput+0x1c/0x30 fs/file_table.c:497
 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 -> 0xffff8881005123a8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 8951 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================