================================================================== BUG: KCSAN: data-race in ext4_da_write_end / ext4_writepages write to 0xffff8881065e01a8 of 8 bytes by task 12781 on cpu 0: mpage_map_and_submit_extent fs/ext4/inode.c:2507 [inline] ext4_writepages+0x13ca/0x1d10 fs/ext4/inode.c:2800 do_writepages+0x7b/0x150 mm/page-writeback.c:2352 __filemap_fdatawrite_range mm/filemap.c:413 [inline] __filemap_fdatawrite mm/filemap.c:421 [inline] filemap_flush+0x132/0x160 mm/filemap.c:448 ext4_alloc_da_blocks+0x4a/0xd0 fs/ext4/inode.c:3164 ext4_release_file+0x5b/0x1d0 fs/ext4/file.c:141 __fput+0x25b/0x4e0 fs/file_table.c:280 ____fput+0x11/0x20 fs/file_table.c:313 task_work_run+0xae/0x130 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301 do_syscall_64+0x56/0x90 arch/x86/entry/common.c:57 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff8881065e01a8 of 8 bytes by task 12791 on cpu 1: ext4_da_write_end+0xfc/0x730 fs/ext4/inode.c:3092 generic_perform_write+0x23e/0x3a0 mm/filemap.c:3671 ext4_buffered_write_iter+0x2f2/0x3f0 fs/ext4/file.c:269 ext4_file_write_iter+0x2e7/0x11d0 fs/ext4/file.c:519 call_write_iter include/linux/fs.h:2114 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x40a/0x750 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:936 splice_direct_to_actor+0x345/0x650 fs/splice.c:891 do_splice_direct+0xf5/0x170 fs/splice.c:979 do_sendfile+0x773/0xda0 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 12791 Comm: syz-executor.3 Not tainted 5.13.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================