==================================================================
BUG: KCSAN: data-race in __anon_vma_prepare / handle_mm_fault

write to 0xffff88810a267e08 of 8 bytes by task 8922 on cpu 0:
 __anon_vma_prepare+0x12f/0x2d0 mm/rmap.c:207
 anon_vma_prepare include/linux/rmap.h:149 [inline]
 do_cow_fault mm/memory.c:4179 [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+0x1729/0x1a50 mm/memory.c:4782
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x91/0x220 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568
 copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:205
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 copyout lib/iov_iter.c:157 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:228 [inline]
 __copy_page_to_iter lib/iov_iter.c:801 [inline]
 copy_page_to_iter+0x2ef/0x940 lib/iov_iter.c:829
 process_vm_rw_pages mm/process_vm_access.c:45 [inline]
 process_vm_rw_single_vec+0x2b8/0x460 mm/process_vm_access.c:117
 process_vm_rw_core mm/process_vm_access.c:215 [inline]
 process_vm_rw+0x347/0x4e0 mm/process_vm_access.c:283
 __do_sys_process_vm_readv mm/process_vm_access.c:295 [inline]
 __se_sys_process_vm_readv mm/process_vm_access.c:291 [inline]
 __x64_sys_process_vm_readv+0x76/0x90 mm/process_vm_access.c:291
 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 0xffff88810a267e08 of 8 bytes by task 8909 on cpu 1:
 anon_vma_prepare include/linux/rmap.h:146 [inline]
 do_cow_fault mm/memory.c:4179 [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+0xb4a/0x1a50 mm/memory.c:4782
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x91/0x220 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568
 copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:205
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
 copyout lib/iov_iter.c:157 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:228 [inline]
 __copy_page_to_iter lib/iov_iter.c:801 [inline]
 copy_page_to_iter+0x2ef/0x940 lib/iov_iter.c:829
 process_vm_rw_pages mm/process_vm_access.c:45 [inline]
 process_vm_rw_single_vec+0x2b8/0x460 mm/process_vm_access.c:117
 process_vm_rw_core mm/process_vm_access.c:215 [inline]
 process_vm_rw+0x347/0x4e0 mm/process_vm_access.c:283
 __do_sys_process_vm_readv mm/process_vm_access.c:295 [inline]
 __se_sys_process_vm_readv mm/process_vm_access.c:291 [inline]
 __x64_sys_process_vm_readv+0x76/0x90 mm/process_vm_access.c:291
 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: 0x0000000000000000 -> 0xffff88813793f1e0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8909 Comm: syz-executor.0 Not tainted 5.14.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================