================================================================== BUG: KCSAN: data-race in filemap_fault / generic_write_end write to 0xffff88811599b6b8 of 8 bytes by task 23655 on cpu 1: i_size_write include/linux/fs.h:897 [inline] generic_write_end+0x99/0x220 fs/buffer.c:2187 ext4_da_write_end+0x57e/0x760 fs/ext4/inode.c:3092 generic_perform_write+0x23b/0x390 mm/filemap.c:3329 ext4_buffered_write_iter+0x2cc/0x3b0 fs/ext4/file.c:270 ext4_file_write_iter+0x76f/0x1010 include/linux/fs.h:805 call_write_iter include/linux/fs.h:1908 [inline] new_sync_write fs/read_write.c:503 [inline] vfs_write+0x607/0x690 fs/read_write.c:578 ksys_write+0xce/0x180 fs/read_write.c:631 __do_sys_write fs/read_write.c:643 [inline] __se_sys_write fs/read_write.c:640 [inline] __x64_sys_write+0x3e/0x50 fs/read_write.c:640 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88811599b6b8 of 8 bytes by task 23663 on cpu 0: i_size_read include/linux/fs.h:875 [inline] filemap_fault+0x9b9/0x11e0 mm/filemap.c:2554 ext4_filemap_fault+0x4b/0x60 fs/ext4/inode.c:6060 __do_fault mm/memory.c:3464 [inline] do_cow_fault+0x1e6/0x770 mm/memory.c:3886 do_fault mm/memory.c:3987 [inline] handle_pte_fault mm/memory.c:4225 [inline] __handle_mm_fault mm/memory.c:4357 [inline] handle_mm_fault+0x1561/0x1930 mm/memory.c:4394 faultin_page mm/gup.c:887 [inline] __get_user_pages+0xac6/0x1150 mm/gup.c:1113 populate_vma_page_range mm/gup.c:1452 [inline] __mm_populate+0x256/0x340 mm/gup.c:1500 mm_populate include/linux/mm.h:2605 [inline] vm_mmap_pgoff+0x13b/0x170 mm/util.c:511 ksys_mmap_pgoff+0x342/0x3a0 mm/mmap.c:1595 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 23663 Comm: syz-executor.1 Not tainted 5.8.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================