================================================================== BUG: KCSAN: data-race in shmem_add_to_page_cache / shmem_recalc_inode write to 0xffff888098c19b48 of 8 bytes by task 9896 on cpu 0: shmem_add_to_page_cache+0x497/0x6b0 mm/shmem.c:643 shmem_getpage_gfp+0x3fd/0x1390 mm/shmem.c:1876 shmem_fault+0x114/0x470 mm/shmem.c:2067 __do_fault+0xae/0x1f0 mm/memory.c:3188 do_read_fault mm/memory.c:3585 [inline] do_fault mm/memory.c:3714 [inline] handle_pte_fault mm/memory.c:3945 [inline] __handle_mm_fault+0x270d/0x2e00 mm/memory.c:4075 handle_mm_fault+0x21b/0x530 mm/memory.c:4112 faultin_page mm/gup.c:640 [inline] __get_user_pages+0x485/0x1130 mm/gup.c:851 populate_vma_page_range+0xe6/0x100 mm/gup.c:1235 __mm_populate+0x168/0x2a0 mm/gup.c:1283 mm_populate include/linux/mm.h:2347 [inline] vm_mmap_pgoff+0x181/0x190 mm/util.c:511 ksys_mmap_pgoff+0x99/0x420 mm/mmap.c:1607 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0x2e/0x40 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff888098c19b48 of 8 bytes by task 9893 on cpu 1: shmem_recalc_inode+0x54/0x190 mm/shmem.c:306 shmem_getpage_gfp+0x552/0x1390 mm/shmem.c:1890 shmem_fault+0x114/0x470 mm/shmem.c:2067 __do_fault+0xae/0x1f0 mm/memory.c:3188 do_shared_fault mm/memory.c:3640 [inline] do_fault mm/memory.c:3718 [inline] handle_pte_fault mm/memory.c:3945 [inline] __handle_mm_fault+0x1ddb/0x2e00 mm/memory.c:4075 handle_mm_fault+0x21b/0x530 mm/memory.c:4112 faultin_page mm/gup.c:640 [inline] __get_user_pages+0x485/0x1130 mm/gup.c:851 __get_user_pages_locked mm/gup.c:1029 [inline] get_user_pages_remote+0x206/0x3e0 mm/gup.c:1175 process_vm_rw_single_vec mm/process_vm_access.c:109 [inline] process_vm_rw_core.isra.0+0x3a4/0x910 mm/process_vm_access.c:216 process_vm_rw+0x1c4/0x1e0 mm/process_vm_access.c:284 __do_sys_process_vm_writev mm/process_vm_access.c:306 [inline] __se_sys_process_vm_writev mm/process_vm_access.c:301 [inline] __x64_sys_process_vm_writev+0x8b/0xb0 mm/process_vm_access.c:301 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 9893 Comm: syz-executor.5 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================