================================================================== BUG: KCSAN: data-race in ext4_setattr / mpage_process_page_bufs write to 0xffff8880b79747b8 of 8 bytes by task 13984 on cpu 0: i_size_write include/linux/fs.h:894 [inline] ext4_setattr+0xd58/0x1320 fs/ext4/inode.c:5365 notify_change+0x82b/0xad0 fs/attr.c:336 do_truncate+0xf9/0x180 fs/open.c:64 handle_truncate fs/namei.c:2887 [inline] do_open fs/namei.c:3233 [inline] path_openat+0x1e51/0x23d0 fs/namei.c:3346 do_filp_open+0x11e/0x1b0 fs/namei.c:3373 do_sys_openat2+0x52e/0x680 fs/open.c:1148 do_sys_open+0xa2/0x110 fs/open.c:1164 __do_sys_openat fs/open.c:1178 [inline] __se_sys_openat fs/open.c:1173 [inline] __x64_sys_openat+0x5d/0x70 fs/open.c:1173 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8880b79747b8 of 8 bytes by task 13980 on cpu 1: mpage_process_page_bufs+0x3f/0x400 fs/ext4/inode.c:2165 mpage_prepare_extent_to_map+0x43b/0x6e0 fs/ext4/inode.c:2595 ext4_writepages+0xb41/0x1e10 fs/ext4/inode.c:2767 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:3144 ext4_release_file+0x107/0x200 fs/ext4/file.c:142 __fput+0x1e9/0x500 fs/file_table.c:280 ____fput+0x1b/0x30 fs/file_table.c:313 task_work_run+0xba/0x120 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2ae/0x2c0 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x38b/0x3b0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 13980 Comm: syz-executor.1 Not tainted 5.7.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================