================================================================== BUG: KCSAN: data-race in ext4_ext_handle_unwritten_extents / ext4_mark_iloc_dirty write to 0xffff88800918b11c of 2 bytes by task 450 on cpu 1: ext4_ext_mark_initialized fs/ext4/ext4_extents.h:218 [inline] ext4_convert_unwritten_extents_endio fs/ext4/extents.c:3716 [inline] ext4_ext_handle_unwritten_extents+0x62e/0xa90 fs/ext4/extents.c:3849 ext4_ext_map_blocks+0x728/0x1fc0 fs/ext4/extents.c:4119 ext4_map_blocks+0x700/0xfc0 fs/ext4/inode.c:628 ext4_convert_unwritten_extents+0x15a/0x2c0 fs/ext4/extents.c:4760 ext4_convert_unwritten_io_end_vec+0xa4/0x130 fs/ext4/extents.c:4799 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+0x198/0x360 fs/ext4/page-io.c:274 process_one_work+0x3e1/0x950 kernel/workqueue.c:2272 worker_thread+0x635/0xb90 kernel/workqueue.c:2418 kthread+0x1fa/0x220 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 read to 0xffff88800918b11c of 4 bytes by task 17287 on cpu 0: ext4_do_update_inode fs/ext4/inode.c:5105 [inline] ext4_mark_iloc_dirty+0xd80/0x1650 fs/ext4/inode.c:5712 __ext4_mark_inode_dirty+0x450/0x610 fs/ext4/inode.c:5906 ext4_dirty_inode+0xa6/0xc0 fs/ext4/inode.c:5942 __mark_inode_dirty+0x74/0x740 fs/fs-writeback.c:2260 mark_inode_dirty include/linux/fs.h:2183 [inline] generic_write_end+0x15e/0x250 fs/buffer.c:2202 ext4_da_write_end+0x59b/0x760 fs/ext4/inode.c:3102 generic_perform_write+0x23e/0x3a0 mm/filemap.c:3322 ext4_buffered_write_iter+0x2e5/0x3d0 fs/ext4/file.c:270 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503 call_write_iter include/linux/fs.h:1903 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4b0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x42a/0x780 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:933 splice_direct_to_actor+0x345/0x650 fs/splice.c:888 do_splice_direct+0xf5/0x170 fs/splice.c:976 do_sendfile+0x5db/0xca0 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 17287 Comm: syz-executor.0 Not tainted 5.10.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================