KCSAN: data-race in expand_downwards / page_add_new_anon

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in expand_downwards / page_add_new_anon_rmap (2) mm				1	1319d	1319d	0/26	auto-closed as invalid on 2020/11/03 10:53
upstream	KCSAN: data-race in expand_downwards / page_add_new_anon_rmap mm				1	1401d	1401d	0/26	auto-closed as invalid on 2020/08/13 06:26

================================================================== BUG: KCSAN: data-race in expand_downwards / page_add_new_anon_rmap write to 0xffff888030e9e708 of 8 bytes by task 27363 on cpu 0: expand_downwards+0x69d/0x990 mm/mmap.c:2552 expand_stack+0x19/0x20 mm/mmap.c:2609 do_user_addr_fault+0x71e/0x830 arch/x86/mm/fault.c:1365 handle_page_fault arch/x86/mm/fault.c:1450 [inline] exc_page_fault+0x94/0x2a0 arch/x86/mm/fault.c:1506 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580 do_strncpy_from_user lib/strncpy_from_user.c:37 [inline] strncpy_from_user+0xf0/0x250 lib/strncpy_from_user.c:139 getname_flags+0xb8/0x3d0 fs/namei.c:149 getname+0x15/0x20 fs/namei.c:209 do_sys_openat2+0x5b/0x240 fs/open.c:1166 do_sys_open fs/open.c:1188 [inline] __do_sys_openat fs/open.c:1204 [inline] __se_sys_openat fs/open.c:1199 [inline] __x64_sys_openat+0xef/0x110 fs/open.c:1199 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff888030e9e708 of 8 bytes by task 27361 on cpu 1: linear_page_index include/linux/pagemap.h:557 [inline] __page_set_anon_rmap mm/rmap.c:1065 [inline] page_add_new_anon_rmap+0x2a5/0x330 mm/rmap.c:1197 do_anonymous_page+0x81a/0xd20 mm/memory.c:3572 handle_pte_fault mm/memory.c:4383 [inline] __handle_mm_fault mm/memory.c:4520 [inline] handle_mm_fault+0x1005/0x17b0 mm/memory.c:4618 faultin_page mm/gup.c:851 [inline] __get_user_pages+0xa32/0xff0 mm/gup.c:1070 populate_vma_page_range mm/gup.c:1403 [inline] __mm_populate+0x24d/0x380 mm/gup.c:1451 mm_populate include/linux/mm.h:2573 [inline] vm_mmap_pgoff+0x14c/0x1d0 mm/util.c:524 ksys_mmap_pgoff+0xe1/0x380 mm/mmap.c:1634 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 27361 Comm: syz-executor.0 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================