[syzbot] [mm?] KASAN: slab-use-after-free Read in __vma_reservation_common

syzbot
2024-04-12T13:32:36Z

Hello,

syzbot found the following issue on:

HEAD commit: 11cb68ad52ac Add linux-next specific files for 20240408
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13a6f483180000
kernel config: https://syzkaller.appspot.com/x/.config?x=727d5608101b5d77
dashboard link: https://syzkaller.appspot.com/bug?extid=ad1b592fc4483655438b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4e90f2d3b1ef/disk-11cb68ad.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d886b454e2cc/vmlinux-11cb68ad.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ed94857c6f92/bzImage-11cb68ad.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ad1b592fc4483655438b@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in is_vm_hugetlb_page include/linux/hugetlb_inline.h:11 [inline]
BUG: KASAN: slab-use-after-free in vma_resv_map mm/hugetlb.c:1150 [inline]
BUG: KASAN: slab-use-after-free in __vma_reservation_common+0xc9/0x7d0 mm/hugetlb.c:2807
Read of size 8 at addr ffff88807c6434f8 by task syz-executor.2/8726

CPU: 0 PID: 8726 Comm: syz-executor.2 Not tainted 6.9.0-rc3-next-20240408-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
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
is_vm_hugetlb_page include/linux/hugetlb_inline.h:11 [inline]
vma_resv_map mm/hugetlb.c:1150 [inline]
__vma_reservation_common+0xc9/0x7d0 mm/hugetlb.c:2807
vma_needs_reservation mm/hugetlb.c:2881 [inline]
restore_reserve_on_error+0x39/0x1d0 mm/hugetlb.c:2931
hugetlb_no_page mm/hugetlb.c:6390 [inline]
hugetlb_fault+0x19ae/0x3710 mm/hugetlb.c:6486
handle_mm_fault+0x18e8/0x1bb0 mm/memory.c:5662
do_user_addr_fault arch/x86/mm/fault.c:1368 [inline]
handle_page_fault arch/x86/mm/fault.c:1511 [inline]
exc_page_fault+0x459/0x900 arch/x86/mm/fault.c:1569
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f9770c2c621
Code: 48 8b 54 24 08 48 85 d2 74 17 8b 44 24 18 0f c8 89 c0 48 89 44 24 18 48 83 fa 01 0f 85 b3 01 00 00 48 8b 44 24 10 8b 54 24 18 <89> 10 e9 15 fd ff ff 48 8b 44 24 10 8b 10 48 8b 44 24 08 48 85 c0
RSP: 002b:00007fff24941e70 EFLAGS: 00010246
RAX: 0000000020000000 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000194 RSI: 0000000000000000 RDI: 000055558dd3e360
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: 00007fff24941fe0 R11: 0000000000000246 R12: 00007f9770801138
R13: fffffffffffffffe R14: 00007f9770800000 R15: 00007f9770801140
</TASK>

Allocated by task 8728:
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:3897 [inline]
slab_alloc_node mm/slub.c:3957 [inline]
kmem_cache_alloc_noprof+0x135/0x290 mm/slub.c:3964
vm_area_alloc+0x24/0x1d0 kernel/fork.c:467
mmap_region+0xc09/0x2020 mm/mmap.c:2852
do_mmap+0x8ad/0xf70 mm/mmap.c:1387
vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:573
ksys_mmap_pgoff+0x53c/0x6e0 mm/mmap.c:1433
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x72/0x7a

Freed by task 15:
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:2190 [inline]
slab_free mm/slub.c:4393 [inline]
kmem_cache_free+0x145/0x340 mm/slub.c:4468
rcu_do_batch kernel/rcu/tree.c:2215 [inline]
rcu_core+0xafd/0x1830 kernel/rcu/tree.c:2489
__do_softirq+0x2c6/0x980 kernel/softirq.c:554

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:2752 [inline]
call_rcu+0x167/0xa70 kernel/rcu/tree.c:2856
remove_vma mm/mmap.c:148 [inline]
remove_mt mm/mmap.c:2334 [inline]
do_vmi_align_munmap+0x155c/0x18c0 mm/mmap.c:2677
do_vmi_munmap+0x24e/0x2d0 mm/mmap.c:2741
mmap_region+0x729/0x2020 mm/mmap.c:2792
do_mmap+0x8ad/0xf70 mm/mmap.c:1387
vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:573
ksys_mmap_pgoff+0x53c/0x6e0 mm/mmap.c:1433
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x72/0x7a

The buggy address belongs to the object at ffff88807c6434d8
which belongs to the cache vm_area_struct of size 184
The buggy address is located 32 bytes inside of
freed 184-byte region [ffff88807c6434d8, ffff88807c643590)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807c643aa8 pfn:0x7c643
memcg:ffff88802cfea301
anon flags: 0xfff80000000000(node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffefff(slab)
raw: 00fff80000000000 ffff8880162a7b40 ffffea00017aa380 dead000000000005
raw: ffff88807c643aa8 000000000010000b 00000001ffffefff ffff88802cfea301
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 8361, tgid -847542916 (dhcpcd-run-hook), ts 8361, free_ts 221237227404
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468
prep_new_page mm/page_alloc.c:1476 [inline]
get_page_from_freelist+0x2ce2/0x2d90 mm/page_alloc.c:3438
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4696
__alloc_pages_node_noprof include/linux/gfp.h:244 [inline]
alloc_pages_node_noprof include/linux/gfp.h:271 [inline]
alloc_slab_page+0x5f/0x120 mm/slub.c:2259
allocate_slab+0x5a/0x2e0 mm/slub.c:2422
new_slab mm/slub.c:2475 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3624
__slab_alloc+0x58/0xa0 mm/slub.c:3714
__slab_alloc_node mm/slub.c:3767 [inline]
slab_alloc_node mm/slub.c:3945 [inline]
kmem_cache_alloc_noprof+0x1c1/0x290 mm/slub.c:3964
vm_area_dup+0x27/0x290 kernel/fork.c:482
dup_mmap kernel/fork.c:697 [inline]
dup_mm kernel/fork.c:1687 [inline]
copy_mm+0xd0f/0x1fd0 kernel/fork.c:1736
copy_process+0x187a/0x3dc0 kernel/fork.c:2389
kernel_clone+0x226/0x8f0 kernel/fork.c:2796
__do_sys_clone kernel/fork.c:2939 [inline]
__se_sys_clone kernel/fork.c:2923 [inline]
__x64_sys_clone+0x258/0x2a0 kernel/fork.c:2923
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x72/0x7a
page last free pid 5098 tgid 5098 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1088 [inline]
free_unref_folios+0xf23/0x19e0 mm/page_alloc.c:2650
folios_put_refs+0x93a/0xa60 mm/swap.c:1022
folio_batch_release include/linux/pagevec.h:101 [inline]
invalidate_inode_pages2_range+0xdfa/0x10e0 mm/truncate.c:670
close_ctree+0x673/0xd20 fs/btrfs/disk-io.c:4367
generic_shutdown_super+0x136/0x2d0 fs/super.c:641
kill_anon_super+0x3b/0x70 fs/super.c:1225
btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2091
deactivate_locked_super+0xc4/0x130 fs/super.c:472
cleanup_mnt+0x426/0x4c0 fs/namespace.c:1267
task_work_run+0x24f/0x310 kernel/task_work.c:180
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x72/0x7a

Memory state around the buggy address:
ffff88807c643380: fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb
ffff88807c643400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807c643480: fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb
^
ffff88807c643500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807c643580: fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb fb
==================================================================

---
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