================================================================== BUG: KCSAN: data-race in ext4_setattr / mpage_process_page_bufs write to 0xffff8880b6d015b0 of 8 bytes by task 7976 on cpu 0: i_size_write include/linux/fs.h:888 [inline] ext4_setattr+0xd58/0x1290 fs/ext4/inode.c:5340 notify_change+0x82b/0xb00 fs/attr.c:336 do_truncate+0xf9/0x180 fs/open.c:64 handle_truncate fs/namei.c:3083 [inline] do_last fs/namei.c:3496 [inline] path_openat+0x1241/0x2f70 fs/namei.c:3607 do_filp_open+0x11e/0x1b0 fs/namei.c:3637 do_sys_openat2+0x4f5/0x620 fs/open.c:1149 do_sys_open+0xa2/0x110 fs/open.c:1165 ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_creat fs/open.c:1233 [inline] __se_sys_creat fs/open.c:1231 [inline] __x64_sys_creat+0x42/0x60 fs/open.c:1231 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8880b6d015b0 of 8 bytes by task 7973 on cpu 1: mpage_process_page_bufs+0x3f/0x400 fs/ext4/inode.c:2166 mpage_prepare_extent_to_map+0x43b/0x6e0 fs/ext4/inode.c:2597 ext4_writepages+0xb00/0x1d40 fs/ext4/inode.c:2769 do_writepages+0x6b/0x170 mm/page-writeback.c:2344 __filemap_fdatawrite_range+0x1bb/0x220 mm/filemap.c:421 __filemap_fdatawrite mm/filemap.c:429 [inline] filemap_flush+0x2a/0x40 mm/filemap.c:456 ext4_alloc_da_blocks+0x72/0x170 fs/ext4/inode.c:3146 ext4_release_file+0x107/0x200 fs/ext4/file.c:142 __fput+0x1c3/0x4f0 fs/file_table.c:280 ____fput+0x1b/0x30 fs/file_table.c:313 task_work_run+0xf5/0x130 kernel/task_work.c:113 get_signal+0x1236/0x1290 kernel/signal.c:2528 do_signal+0x2b/0x670 arch/x86/kernel/signal.c:813 exit_to_usermode_loop+0x24a/0x2c0 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x36e/0x390 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7973 Comm: syz-executor.0 Not tainted 5.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================