syzbot


KASAN: slab-use-after-free Read in hugetlb_fault (2)

Status: upstream: reported on 2024/09/08 18:23
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+2dab93857ee95f2eeb08@syzkaller.appspotmail.com
Fix commit: 98b74bb4d7e9 mm/hugetlb.c: fix UAF of vma in hugetlb fault pathway 2a058ab3286d mm: change vmf_anon_prepare() to __vmf_anon_prepare()
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm]
First crash: 34d, last: 25d
Discussions (2)
Title Replies (including bot) Last reply
[PATCH 1/2] mm: Change vmf_anon_prepare() to __vmf_anon_prepare() 2 (2) 2024/09/14 19:41
[syzbot] [mm?] KASAN: slab-use-after-free Read in hugetlb_fault (2) 4 (5) 2024/09/14 05:50
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in hugetlb_fault mm C done done 6 149d 173d 0/28 auto-obsoleted due to no activity on 2024/08/19 13:32
upstream KASAN: use-after-free Read in hugetlb_fault mm C 383 620d 716d 22/28 fixed on 2023/02/24 13:50

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in __vma_shareable_lock include/linux/hugetlb.h:1278 [inline]
BUG: KASAN: slab-use-after-free in hugetlb_vma_unlock_read mm/hugetlb.c:281 [inline]
BUG: KASAN: slab-use-after-free in hugetlb_no_page mm/hugetlb.c:6380 [inline]
BUG: KASAN: slab-use-after-free in hugetlb_fault+0xfaf/0x3770 mm/hugetlb.c:6485
Read of size 8 at addr ffff88807c17f9d0 by task syz.0.4558/26998

CPU: 1 UID: 0 PID: 26998 Comm: syz.0.4558 Not tainted 6.11.0-rc6-syzkaller-00026-g88fac17500f4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 __vma_shareable_lock include/linux/hugetlb.h:1278 [inline]
 hugetlb_vma_unlock_read mm/hugetlb.c:281 [inline]
 hugetlb_no_page mm/hugetlb.c:6380 [inline]
 hugetlb_fault+0xfaf/0x3770 mm/hugetlb.c:6485
 handle_mm_fault+0x1901/0x1bc0 mm/memory.c:5830
 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f2b63744998
Code: fc 89 37 c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 fa 7f 4c 17 f0 c3 66 0f 1f 84 00 00 00 00 00 48 8b 4c 16 f8 48 8b 36 <48> 89 37 48 89 4c 17 f8 c3 c5 fe 6f 54 16 e0 c5 fe 6f 5c 16 c0 c5
RSP: 002b:00007f2b63a5fb88 EFLAGS: 00010206
RAX: 00000000200002c0 RBX: 0000000000000004 RCX: 00676e7277682f76
RDX: 000000000000000b RSI: 7277682f7665642f RDI: 00000000200002c0
RBP: 00007f2b63937a80 R08: 00007f2b63600000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000009 R12: 000000000014aa5e
R13: 00007f2b63a5fc90 R14: 0000000000000032 R15: fffffffffffffffe
 </TASK>

Allocated by task 27000:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3988 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4044
 vm_area_alloc+0x24/0x1d0 kernel/fork.c:471
 mmap_region+0xc3d/0x2090 mm/mmap.c:2944
 do_mmap+0x8f9/0x1010 mm/mmap.c:1468
 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588
 ksys_mmap_pgoff+0x544/0x720 mm/mmap.c:1514
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 26255:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kmem_cache_free+0x145/0x350 mm/slub.c:4548
 rcu_do_batch kernel/rcu/tree.c:2569 [inline]
 rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2843
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 do_softirq+0x11b/0x1e0 kernel/softirq.c:455
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 __fib6_clean_all+0x327/0x4b0 net/ipv6/ip6_fib.c:2277
 rt6_sync_down_dev net/ipv6/route.c:4908 [inline]
 rt6_disable_ip+0x164/0x7e0 net/ipv6/route.c:4913
 addrconf_ifdown+0x15d/0x1bd0 net/ipv6/addrconf.c:3856
 addrconf_notify+0x3cb/0x1020
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2032 [inline]
 call_netdevice_notifiers net/core/dev.c:2046 [inline]
 dev_close_many+0x33c/0x4c0 net/core/dev.c:1587
 unregister_netdevice_many_notify+0x50b/0x1c40 net/core/dev.c:11327
 unregister_netdevice_many net/core/dev.c:11414 [inline]
 default_device_exit_batch+0xa0f/0xa90 net/core/dev.c:11897
 ops_exit_list net/core/net_namespace.c:178 [inline]
 cleanup_net+0x89d/0xcc0 net/core/net_namespace.c:640
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd10 kernel/workqueue.c:3389
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 __call_rcu_common kernel/rcu/tree.c:3106 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:3210
 remove_vma mm/mmap.c:189 [inline]
 remove_mt mm/mmap.c:2415 [inline]
 do_vmi_align_munmap+0x155c/0x18c0 mm/mmap.c:2758
 do_vmi_munmap+0x261/0x2f0 mm/mmap.c:2830
 mmap_region+0x72f/0x2090 mm/mmap.c:2881
 do_mmap+0x8f9/0x1010 mm/mmap.c:1468
 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588
 ksys_mmap_pgoff+0x544/0x720 mm/mmap.c:1514
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807c17f9b0
 which belongs to the cache vm_area_struct of size 184
The buggy address is located 32 bytes inside of
 freed 184-byte region [ffff88807c17f9b0, ffff88807c17fa68)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c17f
memcg:ffff888028997401
anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000000 ffff88801bafdb40 ffffea0001f89e00 000000000000000d
raw: 0000000000000000 0000000000100010 00000001fdffffff ffff888028997401
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x152cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 26741, tgid 26741 (dhcpcd-run-hook), ts 1341391347767, free_ts 1341166373745
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2321
 allocate_slab+0x5a/0x2f0 mm/slub.c:2484
 new_slab mm/slub.c:2537 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723
 __slab_alloc+0x58/0xa0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4044
 vm_area_dup+0x27/0x290 kernel/fork.c:486
 dup_mmap kernel/fork.c:695 [inline]
 dup_mm kernel/fork.c:1672 [inline]
 copy_mm+0xc7b/0x1f30 kernel/fork.c:1721
 copy_process+0x187a/0x3dc0 kernel/fork.c:2374
 kernel_clone+0x226/0x8f0 kernel/fork.c:2781
 __do_sys_clone kernel/fork.c:2924 [inline]
 __se_sys_clone kernel/fork.c:2908 [inline]
 __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2908
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 26730 tgid 26718 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612
 __folio_put+0x2c8/0x440 mm/swap.c:128
 migrate_folio_move mm/migrate.c:1330 [inline]
 migrate_pages_batch+0x2a76/0x3560 mm/migrate.c:1818
 migrate_pages_sync mm/migrate.c:1884 [inline]
 migrate_pages+0x1f59/0x3460 mm/migrate.c:1993
 do_mbind mm/mempolicy.c:1388 [inline]
 kernel_mbind mm/mempolicy.c:1531 [inline]
 __do_sys_mbind mm/mempolicy.c:1605 [inline]
 __se_sys_mbind+0x1490/0x19f0 mm/mempolicy.c:1601
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807c17f880: fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 00
 ffff88807c17f900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
>ffff88807c17f980: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff88807c17fa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
 ffff88807c17fa80: fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/04 02:32 upstream 88fac17500f4 9d47f20a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce KASAN: slab-use-after-free Read in hugetlb_fault
2024/09/12 17:31 net-next 3cfb5aa10cb7 60e1a995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in hugetlb_fault
* Struck through repros no longer work on HEAD.