syzbot


KASAN: use-after-free Read in anon_vma_interval_tree_insert (2)

Status: moderation: reported on 2022/07/14 12:09
Reported-by: syzbot+43ce57526396bf8a8cc0@syzkaller.appspotmail.com
First crash: 34d, last: 34d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in anon_vma_interval_tree_insert 1 96d 96d 0/23 auto-closed as invalid on 2022/07/11 21:59
linux-4.14 general protection fault in anon_vma_interval_tree_insert 1 486d 486d 0/1 auto-closed as invalid on 2021/08/16 07:22
linux-4.19 general protection fault in anon_vma_interval_tree_insert 1 461d 461d 0/1 auto-closed as invalid on 2021/09/09 17:59
upstream general protection fault in anon_vma_interval_tree_insert (2) 4 264d 348d 0/23 auto-closed as invalid on 2022/02/24 00:52
linux-4.19 KASAN: slab-out-of-bounds Read in anon_vma_interval_tree_insert 1 234d 234d 0/1 auto-closed as invalid on 2022/04/24 23:41

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in vma_start_pgoff mm/interval_tree.c:15 [inline]
BUG: KASAN: use-after-free in avc_start_pgoff mm/interval_tree.c:63 [inline]
BUG: KASAN: use-after-free in __anon_vma_interval_tree_insert mm/interval_tree.c:71 [inline]
BUG: KASAN: use-after-free in anon_vma_interval_tree_insert+0x3e8/0x4b0 mm/interval_tree.c:82
Read of size 8 at addr ffff88807ca72728 by task syz-executor.2/1645

CPU: 1 PID: 1645 Comm: syz-executor.2 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:317 [inline]
 print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
 kasan_report+0xbe/0x1f0 mm/kasan/report.c:495
 vma_start_pgoff mm/interval_tree.c:15 [inline]
 avc_start_pgoff mm/interval_tree.c:63 [inline]
 __anon_vma_interval_tree_insert mm/interval_tree.c:71 [inline]
 anon_vma_interval_tree_insert+0x3e8/0x4b0 mm/interval_tree.c:82
 anon_vma_interval_tree_post_update_vma mm/mmap.c:437 [inline]
 __vma_adjust+0x80d/0x1900 mm/mmap.c:865
 vma_merge+0x6a8/0x870 mm/mmap.c:1135
 userfaultfd_release+0x4b6/0x680 fs/userfaultfd.c:884
 __fput+0x277/0x9d0 fs/file_table.c:317
 task_work_run+0xdd/0x1a0 kernel/task_work.c:177
 get_signal+0x1c5/0x2600 kernel/signal.c:2634
 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop kernel/entry/common.c:166 [inline]
 exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f7418689109
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f74197fd168 EFLAGS: 00000246 ORIG_RAX: 0000000000000013
RAX: fffffffffffffe00 RBX: 00007f741879bf60 RCX: 00007f7418689109
RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00007f74186e30ed R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffe516c65f R14: 00007f74197fd300 R15: 0000000000022000
 </TASK>

Allocated by task 1645:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:436 [inline]
 __kasan_slab_alloc+0x90/0xc0 mm/kasan/common.c:469
 kasan_slab_alloc include/linux/kasan.h:224 [inline]
 slab_post_alloc_hook mm/slab.h:736 [inline]
 slab_alloc_node mm/slub.c:3243 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3258 [inline]
 kmem_cache_alloc+0x2d6/0x4c0 mm/slub.c:3268
 vm_area_dup+0x81/0x380 kernel/fork.c:466
 copy_vma+0x36f/0x890 mm/mmap.c:3325
 move_vma+0x449/0xf60 mm/mremap.c:626
 __do_sys_mremap+0x480/0x16a0 mm/mremap.c:1075
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Freed by task 1645:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:328
 kasan_slab_free include/linux/kasan.h:200 [inline]
 slab_free_hook mm/slub.c:1754 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780
 slab_free mm/slub.c:3534 [inline]
 kmem_cache_free+0xeb/0x5b0 mm/slub.c:3551
 copy_vma+0x6ac/0x890 mm/mmap.c:3352
 move_vma+0x449/0xf60 mm/mremap.c:626
 __do_sys_mremap+0x480/0x16a0 mm/mremap.c:1075
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

The buggy address belongs to the object at ffff88807ca726c0
 which belongs to the cache vm_area_struct of size 152
The buggy address is located 104 bytes inside of
 152-byte region [ffff88807ca726c0, ffff88807ca72758)

The buggy address belongs to the physical page:
page:ffffea0001f29c80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7ca72
memcg:ffff888020788701
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000970780 dead000000000005 ffff888140006b40
raw: 0000000000000000 0000000000120012 00000001ffffffff ffff888020788701
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 3462, tgid 3462 (dhcpcd-run-hook), ts 40586516413, free_ts 40583615146
 prep_new_page mm/page_alloc.c:2535 [inline]
 get_page_from_freelist+0x210d/0x3a30 mm/page_alloc.c:4282
 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5506
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2280
 alloc_slab_page mm/slub.c:1824 [inline]
 allocate_slab+0x27e/0x3d0 mm/slub.c:1969
 new_slab mm/slub.c:2029 [inline]
 ___slab_alloc+0x89d/0xef0 mm/slub.c:3031
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118
 slab_alloc_node mm/slub.c:3209 [inline]
 slab_alloc mm/slub.c:3251 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3258 [inline]
 kmem_cache_alloc+0x3fb/0x4c0 mm/slub.c:3268
 vm_area_dup+0x81/0x380 kernel/fork.c:466
 dup_mmap+0x642/0x1070 kernel/fork.c:640
 dup_mm+0x91/0x370 kernel/fork.c:1520
 copy_mm kernel/fork.c:1569 [inline]
 copy_process+0x3ca8/0x7080 kernel/fork.c:2237
 kernel_clone+0xe7/0xab0 kernel/fork.c:2652
 __do_sys_clone+0xba/0x100 kernel/fork.c:2786
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1453 [inline]
 free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1503
 free_unref_page_prepare mm/page_alloc.c:3383 [inline]
 free_unref_page_list+0x16f/0xb90 mm/page_alloc.c:3525
 release_pages+0xbe8/0x1810 mm/swap.c:1017
 tlb_batch_pages_flush+0xa8/0x1a0 mm/mmu_gather.c:58
 tlb_flush_mmu_free mm/mmu_gather.c:255 [inline]
 tlb_flush_mmu mm/mmu_gather.c:262 [inline]
 tlb_finish_mmu+0x147/0x7e0 mm/mmu_gather.c:353
 exit_mmap+0x1fe/0x720 mm/mmap.c:3212
 __mmput+0x128/0x4c0 kernel/fork.c:1180
 mmput+0x5c/0x70 kernel/fork.c:1201
 exit_mm kernel/exit.c:510 [inline]
 do_exit+0xa09/0x29f0 kernel/exit.c:782
 do_group_exit+0xd2/0x2f0 kernel/exit.c:925
 __do_sys_exit_group kernel/exit.c:936 [inline]
 __se_sys_exit_group kernel/exit.c:934 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:934
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Memory state around the buggy address:
 ffff88807ca72600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807ca72680: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
>ffff88807ca72700: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
                                  ^
 ffff88807ca72780: fc fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88807ca72800: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fa fb
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-linux-next-kasan-gce-root 2022/07/14 05:23 linux-next cb71b93c2dc3 5d921b08 .config log report info KASAN: use-after-free Read in anon_vma_interval_tree_insert