[syzbot] KASAN: stack-out-of-bounds Write in check_move_unevictable_pages

From: syzbot
Date: Tue Jun 07 2022 - 09:11:42 EST

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Hello,

syzbot found the following issue on:

HEAD commit: 73d0e32571a0 Add linux-next specific files for 20220607
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=12191700080000
kernel config: https://syzkaller.appspot.com/x/.config?x=448ee2b64e828049
dashboard link: https://syzkaller.appspot.com/bug?extid=8847ae8c7bc46bc9c10e
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8847ae8c7bc46bc9c10e@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
==================================================================
BUG: KASAN: stack-out-of-bounds in folio_batch_add include/linux/pagevec.h:130 [inline]
BUG: KASAN: stack-out-of-bounds in check_move_unevictable_pages+0x3f6/0x440 mm/vmscan.c:4857
Write of size 8 at addr ffffc9000ce5fbd8 by task syz-executor.0/17282

CPU: 0 PID: 17282 Comm: syz-executor.0 Not tainted 5.19.0-rc1-next-20220607-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0xf/0x495 mm/kasan/report.c:313
print_report mm/kasan/report.c:429 [inline]
kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491
folio_batch_add include/linux/pagevec.h:130 [inline]
check_move_unevictable_pages+0x3f6/0x440 mm/vmscan.c:4857
drm_gem_check_release_pagevec drivers/gpu/drm/drm_gem.c:511 [inline]
drm_gem_put_pages+0x341/0x3f0 drivers/gpu/drm/drm_gem.c:642
drm_gem_shmem_put_pages_locked+0x13e/0x230 drivers/gpu/drm/drm_gem_shmem_helper.c:237
drm_gem_shmem_put_pages drivers/gpu/drm/drm_gem_shmem_helper.c:252 [inline]
drm_gem_shmem_vm_close+0x45/0x70 drivers/gpu/drm/drm_gem_shmem_helper.c:588
remove_vma+0x81/0x130 mm/mmap.c:187
exit_mmap+0x2a1/0x750 mm/mmap.c:3215
__mmput+0x128/0x4c0 kernel/fork.c:1180
mmput+0x5c/0x70 kernel/fork.c:1201
exit_mm kernel/exit.c:510 [inline]
do_exit+0xa18/0x2a00 kernel/exit.c:782
do_group_exit+0xd2/0x2f0 kernel/exit.c:925
get_signal+0x2542/0x2600 kernel/signal.c:2857
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: 0033:0x7f832a289109
Code: Unable to access opcode bytes at RIP 0x7f832a2890df.
RSP: 002b:00007f832b461218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f832a39bf68 RCX: 00007f832a289109
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f832a39bf68
RBP: 00007f832a39bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f832a39bf6c
R13: 00007ffc361fd38f R14: 00007f832b461300 R15: 0000000000022000
</TASK>

The buggy address belongs to stack of task syz-executor.0/17282
and is located at offset 16 in frame:
do_exit+0x0/0x2a00 kernel/exit.c:423

This frame has 1 object:
[32, 48) 'dead'

The buggy address belongs to the virtual mapping at
[ffffc9000ce58000, ffffc9000ce61000) created by:
kernel_clone+0xe7/0xab0 kernel/fork.c:2648

The buggy address belongs to the physical page:
page:ffffea00007de500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f794
memcg:ffff888076335e82
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff888076335e82
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 17263, tgid 17263 (syz-executor.0), ts 1021283919880, free_ts 1021173517931
prep_new_page mm/page_alloc.c:2460 [inline]
get_page_from_freelist+0xa64/0x3d10 mm/page_alloc.c:4279
__alloc_pages+0x1c7/0x510 mm/page_alloc.c:5503
alloc_pages+0x1aa/0x310 mm/mempolicy.c:2279
vm_area_alloc_pages mm/vmalloc.c:2926 [inline]
__vmalloc_area_node mm/vmalloc.c:2994 [inline]
__vmalloc_node_range+0x735/0x13b0 mm/vmalloc.c:3164
alloc_thread_stack_node kernel/fork.c:311 [inline]
dup_task_struct kernel/fork.c:971 [inline]
copy_process+0x1568/0x7010 kernel/fork.c:2064
kernel_clone+0xe7/0xab0 kernel/fork.c:2648
__do_sys_clone+0xba/0x100 kernel/fork.c:2782
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:1375 [inline]
free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1425
free_unref_page_prepare mm/page_alloc.c:3311 [inline]
free_unref_page+0x19/0x7b0 mm/page_alloc.c:3426
__vunmap+0x86b/0xd50 mm/vmalloc.c:2664
__vfree+0x3c/0xd0 mm/vmalloc.c:2712
vfree+0x5a/0x90 mm/vmalloc.c:2743
kvfree+0x2e/0x50 mm/util.c:621
kvm_destroy_dirty_bitmap arch/x86/kvm/../../../virt/kvm/kvm_main.c:912 [inline]
kvm_free_memslot arch/x86/kvm/../../../virt/kvm/kvm_main.c:919 [inline]
kvm_free_memslots.part.0+0xd5/0x1a0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:942
kvm_free_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:938 [inline]
kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1264 [inline]
kvm_put_kvm+0x83e/0xb70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1294
kvm_vcpu_release+0x4d/0x70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3713
__fput+0x277/0x9d0 fs/file_table.c:317
task_work_run+0xdd/0x1a0 kernel/task_work.c:177
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop kernel/entry/common.c:169 [inline]
exit_to_user_mode_prepare+0x23c/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

Memory state around the buggy address:
ffffc9000ce5fa80: 00 00 00 00 00 00 00 f3 f3 f3 f3 00 00 00 00 00
ffffc9000ce5fb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000ce5fb80: 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f3
^
ffffc9000ce5fc00: f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc9000ce5fc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

---
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Next message: Greg KH: "Re: [PATCH v2] serial: 8250_omap: Fix syntax errors in comments"
Previous message: syzbot: "[syzbot] KASAN: use-after-free Read in copy_page_from_iter_atomic (2)"
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