================================================================== BUG: KCSAN: data-race in ext4_mb_regular_allocator / mb_free_blocks write to 0xffff888101f8e884 of 4 bytes by task 16041 on cpu 0: mb_free_blocks+0x156/0xb60 fs/ext4/mballoc.c:1464 ext4_free_blocks+0x135d/0x1be0 fs/ext4/mballoc.c:5449 ext4_ext_try_to_merge_up fs/ext4/extents.c:1830 [inline] ext4_ext_try_to_merge+0x2fa/0x310 fs/ext4/extents.c:1857 ext4_swap_extents+0x102d/0x13a0 fs/ext4/extents.c:5693 move_extent_per_page+0x143c/0x16c0 fs/ext4/move_extent.c:339 ext4_move_extents+0xaac/0xc00 fs/ext4/move_extent.c:673 __ext4_ioctl fs/ext4/ioctl.c:992 [inline] ext4_ioctl+0x218f/0x35e0 fs/ext4/ioctl.c:1332 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff888101f8e884 of 4 bytes by task 16049 on cpu 1: ext4_mb_good_group_nolock fs/ext4/mballoc.c:2153 [inline] ext4_mb_regular_allocator+0x8a6/0x1900 fs/ext4/mballoc.c:2386 ext4_mb_new_blocks+0x6f8/0x1150 fs/ext4/mballoc.c:4975 ext4_new_meta_blocks+0x84/0x180 fs/ext4/balloc.c:679 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+0x143c/0x16c0 fs/ext4/move_extent.c:339 ext4_move_extents+0xaac/0xc00 fs/ext4/move_extent.c:673 __ext4_ioctl fs/ext4/ioctl.c:992 [inline] ext4_ioctl+0x218f/0x35e0 fs/ext4/ioctl.c:1332 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 16049 Comm: syz-executor.4 Tainted: G W 5.12.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================