================================================================== BUG: KCSAN: data-race in mb_mark_used / mb_update_avg_fragment_size write to 0xffff8881017d5a94 of 4 bytes by task 5905 on cpu 1: mb_mark_used+0x13b/0xc50 fs/ext4/mballoc.c:1942 ext4_mb_use_best_found+0x102/0x320 fs/ext4/mballoc.c:2014 ext4_mb_measure_extent fs/ext4/mballoc.c:2130 [inline] ext4_mb_complex_scan_group+0x349/0x850 fs/ext4/mballoc.c:2360 ext4_mb_regular_allocator+0x1a22/0x2520 fs/ext4/mballoc.c:2759 ext4_mb_new_blocks+0x762/0x1f90 fs/ext4/mballoc.c:5514 ext4_new_meta_blocks+0x84/0x180 fs/ext4/balloc.c:693 ext4_ext_grow_indepth fs/ext4/extents.c:1276 [inline] ext4_ext_create_new_leaf fs/ext4/extents.c:1380 [inline] ext4_ext_insert_extent+0x9b3/0x2bc0 fs/ext4/extents.c:2054 ext4_split_extent_at+0x6f2/0xb40 fs/ext4/extents.c:3208 ext4_force_split_extent_at fs/ext4/extents.c:305 [inline] ext4_swap_extents+0xd76/0x13a0 fs/ext4/extents.c:5664 move_extent_per_page fs/ext4/move_extent.c:339 [inline] ext4_move_extents+0x1fec/0x2250 fs/ext4/move_extent.c:673 __ext4_ioctl fs/ext4/ioctl.c:938 [inline] ext4_ioctl+0x12f4/0x1df0 fs/ext4/ioctl.c:1224 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:1069 [inline] __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:1055 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff8881017d5a94 of 4 bytes by task 5927 on cpu 0: ext4_mb_avg_fragment_size_cmp fs/ext4/mballoc.c:835 [inline] ext4_mb_rb_insert fs/ext4/mballoc.c:811 [inline] mb_update_avg_fragment_size+0x184/0x260 fs/ext4/mballoc.c:859 mb_mark_used+0xae0/0xc50 fs/ext4/mballoc.c:1993 ext4_mb_use_best_found+0x102/0x320 fs/ext4/mballoc.c:2014 ext4_mb_try_best_found+0x234/0x3d0 fs/ext4/mballoc.c:2180 ext4_mb_regular_allocator+0x22bd/0x2520 fs/ext4/mballoc.c:2778 ext4_mb_new_blocks+0x762/0x1f90 fs/ext4/mballoc.c:5514 ext4_ext_map_blocks+0x1569/0x1f00 fs/ext4/extents.c:4238 ext4_map_blocks+0x70d/0xef0 fs/ext4/inode.c:638 ext4_alloc_file_blocks+0x271/0x720 fs/ext4/extents.c:4425 ext4_fallocate+0x2a7/0x4d0 fs/ext4/extents.c:4705 vfs_fallocate+0x463/0x660 fs/open.c:311 file_ioctl fs/ioctl.c:497 [inline] do_vfs_ioctl+0x1322/0x1410 fs/ioctl.c:1048 __do_sys_ioctl fs/ioctl.c:1067 [inline] __se_sys_ioctl+0x83/0x140 fs/ioctl.c:1055 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 5927 Comm: syz-executor.0 Not tainted 5.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================