================================================================== BUG: KCSAN: data-race in filemap_fault / generic_write_end write to 0xffff8881065e0680 of 8 bytes by task 5455 on cpu 1: i_size_write include/linux/fs.h:871 [inline] generic_write_end+0x96/0x180 fs/buffer.c:2182 ext4_da_write_end+0x59b/0x730 fs/ext4/inode.c:3110 generic_perform_write+0x22a/0x3c0 mm/filemap.c:3667 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] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x69d/0x770 fs/read_write.c:605 ksys_write+0xce/0x180 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:667 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff8881065e0680 of 8 bytes by task 5463 on cpu 0: i_size_read include/linux/fs.h:849 [inline] filemap_fault+0x8a/0x7b0 mm/filemap.c:2971 ext4_filemap_fault+0x4b/0x60 fs/ext4/inode.c:6194 __do_fault mm/memory.c:3857 [inline] do_cow_fault mm/memory.c:4192 [inline] do_fault mm/memory.c:4293 [inline] handle_pte_fault mm/memory.c:4549 [inline] __handle_mm_fault mm/memory.c:4684 [inline] handle_mm_fault+0x126f/0x1a50 mm/memory.c:4782 faultin_page mm/gup.c:951 [inline] __get_user_pages+0x32b/0xbc0 mm/gup.c:1173 populate_vma_page_range mm/gup.c:1506 [inline] __mm_populate+0x24d/0x380 mm/gup.c:1612 mm_populate include/linux/mm.h:2623 [inline] vm_mmap_pgoff+0x142/0x1d0 mm/util.c:524 ksys_mmap_pgoff+0x2a8/0x380 mm/mmap.c:1635 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x0000000000df3000 -> 0x0000000000df6000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 5463 Comm: syz-executor.3 Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================