================================================================== BUG: KCSAN: data-race in ext4_ext_handle_unwritten_extents / ext4_mark_iloc_dirty write to 0xffff8880ad0e7adc of 2 bytes by task 21 on cpu 1: ext4_ext_mark_initialized fs/ext4/ext4_extents.h:218 [inline] ext4_convert_unwritten_extents_endio fs/ext4/extents.c:3721 [inline] ext4_ext_handle_unwritten_extents+0x609/0xaa0 fs/ext4/extents.c:3854 ext4_ext_map_blocks+0x758/0x20c0 fs/ext4/extents.c:4124 ext4_map_blocks+0x6d3/0xf60 fs/ext4/inode.c:626 ext4_convert_unwritten_extents+0x16a/0x2d0 fs/ext4/extents.c:4755 ext4_convert_unwritten_io_end_vec+0xa4/0x130 fs/ext4/extents.c:4794 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+0x3e1/0x9a0 kernel/workqueue.c:2269 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415 kthread+0x20d/0x230 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 read to 0xffff8880ad0e7adc of 4 bytes by task 19951 on cpu 0: ext4_do_update_inode fs/ext4/inode.c:5042 [inline] ext4_mark_iloc_dirty+0xd6c/0x1660 fs/ext4/inode.c:5624 __ext4_mark_inode_dirty+0x448/0x630 fs/ext4/inode.c:5818 ext4_dirty_inode+0xa6/0xc0 fs/ext4/inode.c:5854 __mark_inode_dirty+0x72/0x7e0 fs/fs-writeback.c:2258 mark_inode_dirty include/linux/fs.h:2192 [inline] generic_write_end+0x166/0x220 fs/buffer.c:2203 ext4_da_write_end+0x57e/0x760 fs/ext4/inode.c:3092 generic_perform_write+0x23b/0x390 mm/filemap.c:3329 ext4_buffered_write_iter+0x2cc/0x3b0 fs/ext4/file.c:270 ext4_file_write_iter+0x76f/0x1010 include/linux/fs.h:805 call_write_iter include/linux/fs.h:1908 [inline] do_iter_readv_writev+0x321/0x3c0 fs/read_write.c:713 do_iter_write+0x10e/0x470 fs/read_write.c:1018 vfs_iter_write+0x4c/0x70 fs/read_write.c:1059 iter_file_splice_write+0x41a/0x770 fs/splice.c:750 do_splice_from fs/splice.c:846 [inline] direct_splice_actor+0x95/0x160 fs/splice.c:1016 splice_direct_to_actor+0x365/0x660 fs/splice.c:971 do_splice_direct+0xf2/0x170 fs/splice.c:1059 do_sendfile+0x562/0xb10 fs/read_write.c:1540 __do_sys_sendfile64 fs/read_write.c:1601 [inline] __se_sys_sendfile64 fs/read_write.c:1587 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 19951 Comm: syz-executor.4 Not tainted 5.8.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================