================================================================== BUG: KCSAN: data-race in generic_write_end / mpage_submit_page write to 0xffff88811ccbf5b8 of 8 bytes by task 14556 on cpu 0: i_size_write include/linux/fs.h:894 [inline] generic_write_end+0xd4/0x290 fs/buffer.c:2177 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 read to 0xffff88811ccbf5b8 of 8 bytes by task 25 on cpu 1: mpage_submit_page+0x78/0x190 fs/ext4/inode.c:2067 mpage_map_and_submit_buffers+0x35d/0x610 fs/ext4/inode.c:2317 mpage_map_and_submit_extent fs/ext4/inode.c:2456 [inline] ext4_writepages+0x11af/0x1e10 fs/ext4/inode.c:2770 do_writepages+0x6b/0x170 mm/page-writeback.c:2344 __writeback_single_inode+0xaa/0x910 fs/fs-writeback.c:1452 writeback_sb_inodes+0x4c8/0xa10 fs/fs-writeback.c:1716 wb_writeback+0x1f9/0x6a0 fs/fs-writeback.c:1892 wb_do_writeback fs/fs-writeback.c:2037 [inline] wb_workfn+0x215/0x970 fs/fs-writeback.c:2078 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 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 25 Comm: kworker/u4:2 Not tainted 5.7.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-8:0) ==================================================================