================================================================== BUG: KCSAN: data-race in ext4_ext_try_to_merge_right / ext4_mark_iloc_dirty write to 0xffff88811e5279c2 of 2 bytes by task 181 on cpu 1: le16_add_cpu include/linux/byteorder/generic.h:146 [inline] ext4_ext_try_to_merge_right+0x15a/0x2a0 fs/ext4/extents.c:1768 ext4_ext_try_to_merge+0x337/0x360 fs/ext4/extents.c:1842 ext4_convert_unwritten_extents_endio fs/ext4/extents.c:3710 [inline] ext4_ext_handle_unwritten_extents+0x291/0x18c0 fs/ext4/extents.c:3837 ext4_ext_map_blocks+0xa7e/0x1fb0 fs/ext4/extents.c:4098 ext4_map_blocks+0x230/0xcf0 fs/ext4/inode.c:621 ext4_convert_unwritten_extents+0x18b/0x3b0 fs/ext4/extents.c:4729 ext4_convert_unwritten_io_end_vec+0xe0/0x1b0 fs/ext4/extents.c:4764 ext4_end_io_end fs/ext4/page-io.c:187 [inline] ext4_do_flush_completed_IO fs/ext4/page-io.c:260 [inline] ext4_end_io_rsv_work+0x2c2/0x400 fs/ext4/page-io.c:274 process_one_work+0x424/0x930 kernel/workqueue.c:2268 worker_thread+0x9a/0x7e0 kernel/workqueue.c:2414 kthread+0x203/0x230 kernel/kthread.c:268 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 read to 0xffff88811e5279c0 of 4 bytes by task 12555 on cpu 0: ext4_do_update_inode fs/ext4/inode.c:5023 [inline] ext4_mark_iloc_dirty+0xa37/0x1580 fs/ext4/inode.c:5603 ext4_mark_inode_dirty+0xe6/0x420 fs/ext4/inode.c:5796 ext4_dirty_inode+0xad/0xd0 fs/ext4/inode.c:5827 __mark_inode_dirty+0x5b7/0x940 fs/fs-writeback.c:2258 mark_inode_dirty include/linux/fs.h:2189 [inline] generic_write_end+0x24c/0x290 fs/buffer.c:2193 ext4_da_write_end+0x162/0x690 fs/ext4/inode.c:3090 generic_perform_write+0x1d7/0x320 mm/filemap.c:3313 ext4_buffered_write_iter+0x14e/0x280 fs/ext4/file.c:270 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write+0x303/0x400 fs/read_write.c:484 __vfs_write+0x9e/0xb0 fs/read_write.c:497 vfs_write fs/read_write.c:559 [inline] vfs_write+0x189/0x380 fs/read_write.c:543 ksys_write+0xc5/0x1a0 fs/read_write.c:612 __do_sys_write fs/read_write.c:624 [inline] __se_sys_write fs/read_write.c:621 [inline] __x64_sys_write+0x49/0x60 fs/read_write.c:621 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 12555 Comm: syz-executor.2 Not tainted 5.7.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================