================================================================== BUG: KASAN: use-after-free in filemap_fault+0x25f5/0x2a00 mm/filemap.c:2559 Read of size 8 at addr ffff888085962358 by task syz-executor2/11178 CPU: 0 PID: 11178 Comm: syz-executor2 Not tainted 4.20.0-next-20190107 #6 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 filemap_fault+0x25f5/0x2a00 mm/filemap.c:2559 ext4_filemap_fault+0x83/0xaf fs/ext4/inode.c:6327 __do_fault+0x176/0x7b0 mm/memory.c:3013 do_cow_fault mm/memory.c:3453 [inline] do_fault mm/memory.c:3552 [inline] handle_pte_fault mm/memory.c:3781 [inline] __handle_mm_fault+0x13db/0x55a0 mm/memory.c:3905 handle_mm_fault+0x4ec/0xc80 mm/memory.c:3942 faultin_page mm/gup.c:535 [inline] __get_user_pages+0x8f7/0x1e10 mm/gup.c:738 populate_vma_page_range+0x2bc/0x3b0 mm/gup.c:1247 __mm_populate+0x27e/0x4c0 mm/gup.c:1295 do_mlock+0x351/0x830 mm/mlock.c:710 __do_sys_mlock mm/mlock.c:718 [inline] __se_sys_mlock mm/mlock.c:716 [inline] __x64_sys_mlock+0x59/0x80 mm/mlock.c:716 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7e5d387c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000095 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000002000 RDI: 0000000020006000 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7e5d3886d4 R13: 00000000004c3b40 R14: 00000000004d68c8 R15: 00000000ffffffff Allocated by task 11175: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] kasan_kmalloc mm/kasan/common.c:482 [inline] kasan_kmalloc+0xcf/0xe0 mm/kasan/common.c:455 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:397 kmem_cache_alloc+0x12d/0x710 mm/slab.c:3541 vm_area_dup+0x7a/0x230 kernel/fork.c:339 __split_vma+0xad/0x570 mm/mmap.c:2659 split_vma+0xa6/0xf0 mm/mmap.c:2717 mlock_fixup+0x456/0x610 mm/mlock.c:545 apply_vma_lock_flags+0x2e8/0x400 mm/mlock.c:614 do_mlock+0x2f4/0x830 mm/mlock.c:704 __do_sys_mlock2 mm/mlock.c:731 [inline] __se_sys_mlock2 mm/mlock.c:721 [inline] __x64_sys_mlock2+0xc2/0x100 mm/mlock.c:721 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 11175: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:444 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452 __cache_free mm/slab.c:3485 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3747 vm_area_free+0x1d/0x30 kernel/fork.c:350 remove_vma+0x142/0x180 mm/mmap.c:185 remove_vma_list mm/mmap.c:2585 [inline] __do_munmap+0x72e/0xef0 mm/mmap.c:2828 do_munmap mm/mmap.c:2836 [inline] mmap_region+0x698/0x1ca0 mm/mmap.c:1729 do_mmap+0xa09/0x1220 mm/mmap.c:1559 do_mmap_pgoff include/linux/mm.h:2421 [inline] vm_mmap_pgoff+0x20b/0x2b0 mm/util.c:350 ksys_mmap_pgoff+0x4f8/0x650 mm/mmap.c:1609 __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+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888085962318 which belongs to the cache vm_area_struct(49:syz2) of size 200 The buggy address is located 64 bytes inside of 200-byte region [ffff888085962318, ffff8880859623e0) The buggy address belongs to the page: page:ffffea0002165880 count:1 mapcount:0 mapping:ffff8880a9232000 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00028310c8 ffffea00027bdc88 ffff8880a9232000 raw: 0000000000000000 ffff888085962000 000000010000000f ffff888057022ec0 page dumped because: kasan: bad access detected page->mem_cgroup:ffff888057022ec0 Memory state around the buggy address: ffff888085962200: fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888085962280: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc >ffff888085962300: fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888085962380: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888085962400: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================