Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <000000000000599fea0600073558@google.com>
In-Reply-To: <000000000000599fea0600073558@google.com>
From:   Hyeonggon Yoo <42.hyeyoo@gmail.com>
Date:   Mon, 10 Jul 2023 00:44:55 +0900
Message-ID: <CAB=+i9Qc-enAP6dRJVb+0C1+XRf1NQkuOLeur57L7qKHc-A=og@mail.gmail.com>
Subject: Re: [syzbot] [mm?] KASAN: slab-out-of-bounds Read in shrink_folio_list
To:     syzbot <syzbot+c19a171264b968bf389b@syzkaller.appspotmail.com>
Cc:     akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, syzkaller-bugs@googlegroups.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Sun, Jul 9, 2023 at 2:33=E2=80=AFPM syzbot
<syzbot+c19a171264b968bf389b@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    123212f53f3e Add linux-next specific files for 20230707
> git tree:       linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=3D1542771ca8000=
0
> kernel config:  https://syzkaller.appspot.com/x/.config?x=3D15ec80b62f588=
543
> dashboard link: https://syzkaller.appspot.com/bug?extid=3Dc19a171264b968b=
f389b
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binuti=
ls for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=3D1284666aa80=
000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=3D12b142bca8000=
0
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/098f7ee2237c/dis=
k-123212f5.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/88defebbfc49/vmlinu=
x-123212f5.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/d5e9343ec16a/b=
zImage-123212f5.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the comm=
it:
> Reported-by: syzbot+c19a171264b968bf389b@syzkaller.appspotmail.com
>
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> BUG: KASAN: slab-out-of-bounds in instrument_atomic_read include/linux/in=
strumented.h:68 [inline]
> BUG: KASAN: slab-out-of-bounds in _test_bit include/asm-generic/bitops/in=
strumented-non-atomic.h:141 [inline]
> BUG: KASAN: slab-out-of-bounds in mapping_release_always include/linux/pa=
gemap.h:279 [inline]
> BUG: KASAN: slab-out-of-bounds in folio_needs_release mm/internal.h:187 [=
inline]
> BUG: KASAN: slab-out-of-bounds in shrink_folio_list+0x2dbf/0x3e60 mm/vmsc=
an.c:2067
> Read of size 8 at addr ffff888078d2bda1 by task syz-executor321/5029

This should now be fixed:
https://lore.kernel.org/mm-commits/20230707185641.5196AC433C7@smtp.kernel.o=
rg/T/#u

#syz fix: mm: call folio_mapping() inside folio_needs_release()

> CPU: 1 PID: 5029 Comm: syz-executor321 Not tainted 6.4.0-next-20230707-sy=
zkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS G=
oogle 07/03/2023
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:88 [inline]
>  dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
>  print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:364
>  print_report mm/kasan/report.c:475 [inline]
>  kasan_report+0x11d/0x130 mm/kasan/report.c:588
>  check_region_inline mm/kasan/generic.c:181 [inline]
>  kasan_check_range+0xf0/0x190 mm/kasan/generic.c:187
>  instrument_atomic_read include/linux/instrumented.h:68 [inline]
>  _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inli=
ne]
>  mapping_release_always include/linux/pagemap.h:279 [inline]
>  folio_needs_release mm/internal.h:187 [inline]
>  shrink_folio_list+0x2dbf/0x3e60 mm/vmscan.c:2067
>  reclaim_folio_list+0xd0/0x390 mm/vmscan.c:2801
>  reclaim_pages+0x442/0x670 mm/vmscan.c:2837
>  madvise_cold_or_pageout_pte_range+0x100e/0x1ee0 mm/madvise.c:533
>  walk_pmd_range mm/pagewalk.c:140 [inline]
>  walk_pud_range mm/pagewalk.c:218 [inline]
>  walk_p4d_range mm/pagewalk.c:253 [inline]
>  walk_pgd_range+0x9e7/0x1470 mm/pagewalk.c:290
>  __walk_page_range+0x651/0x780 mm/pagewalk.c:392
>  walk_page_range+0x311/0x4a0 mm/pagewalk.c:490
>  madvise_pageout_page_range mm/madvise.c:591 [inline]
>  madvise_pageout+0x2fe/0x560 mm/madvise.c:618
>  madvise_vma_behavior+0x61a/0x21a0 mm/madvise.c:1039
>  madvise_walk_vmas+0x1c7/0x2b0 mm/madvise.c:1268
>  do_madvise.part.0+0x276/0x490 mm/madvise.c:1448
>  do_madvise mm/madvise.c:1461 [inline]
>  __do_sys_madvise mm/madvise.c:1461 [inline]
>  __se_sys_madvise mm/madvise.c:1459 [inline]
>  __x64_sys_madvise+0x117/0x150 mm/madvise.c:1459
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f0290b79c29
> Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f=
7 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 c0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffe42da7dc8 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
> RAX: ffffffffffffffda RBX: 00007f0290be7ed0 RCX: 00007f0290b79c29
> RDX: 0000000000000015 RSI: 0000000000600003 RDI: 0000000020000000
> RBP: 00007ffe42da7dd8 R08: 00007f0290be7e40 R09: 00007f0290be7e40
> R10: 00007ffe42da7840 R11: 0000000000000246 R12: 00007ffe42da7de0
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
>  </TASK>
>
> Allocated by task 5019:
>  kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
>  kasan_set_track+0x25/0x30 mm/kasan/common.c:52
>  __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:328
>  kasan_slab_alloc include/linux/kasan.h:186 [inline]
>  slab_post_alloc_hook mm/slab.h:762 [inline]
>  slab_alloc_node mm/slub.c:3470 [inline]
>  slab_alloc mm/slub.c:3478 [inline]
>  __kmem_cache_alloc_lru mm/slub.c:3485 [inline]
>  kmem_cache_alloc+0x173/0x390 mm/slub.c:3494
>  anon_vma_alloc mm/rmap.c:94 [inline]
>  anon_vma_fork+0xe2/0x630 mm/rmap.c:361
>  dup_mmap+0xc0f/0x14b0 kernel/fork.c:732
>  dup_mm kernel/fork.c:1694 [inline]
>  copy_mm kernel/fork.c:1743 [inline]
>  copy_process+0x6663/0x75c0 kernel/fork.c:2509
>  kernel_clone+0xeb/0x890 kernel/fork.c:2917
>  __do_sys_clone+0xba/0x100 kernel/fork.c:3060
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> The buggy address belongs to the object at ffff888078d2bcc0
>  which belongs to the cache anon_vma of size 208
> The buggy address is located 17 bytes to the right of
>  allocated 208-byte region [ffff888078d2bcc0, ffff888078d2bd90)
>
> The buggy address belongs to the physical page:
> page:ffffea0001e34ac0 refcount:1 mapcount:0 mapping:0000000000000000 inde=
x:0x0 pfn:0x78d2b
> ksm flags: 0xfff00000000200(slab|node=3D0|zone=3D1|lastcpupid=3D0x7ff)
> page_type: 0xffffffff()
> raw: 00fff00000000200 ffff888014674140 ffffea0000ad6100 dead000000000003
> raw: 0000000000000000 00000000800f000f 00000001ffffffff 0000000000000000
> 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 4694, tgid 4694 (dhcpcd), ts 64=
749636388, free_ts 46253751886
>  set_page_owner include/linux/page_owner.h:31 [inline]
>  post_alloc_hook+0x2db/0x350 mm/page_alloc.c:1569
>  prep_new_page mm/page_alloc.c:1576 [inline]
>  get_page_from_freelist+0xfd9/0x2c40 mm/page_alloc.c:3256
>  __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4512
>  alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279
>  alloc_slab_page mm/slub.c:1862 [inline]
>  allocate_slab+0x25f/0x390 mm/slub.c:2009
>  new_slab mm/slub.c:2062 [inline]
>  ___slab_alloc+0xbc3/0x15d0 mm/slub.c:3215
>  __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3314
>  __slab_alloc_node mm/slub.c:3367 [inline]
>  slab_alloc_node mm/slub.c:3460 [inline]
>  slab_alloc mm/slub.c:3478 [inline]
>  __kmem_cache_alloc_lru mm/slub.c:3485 [inline]
>  kmem_cache_alloc+0x371/0x390 mm/slub.c:3494
>  anon_vma_alloc mm/rmap.c:94 [inline]
>  anon_vma_fork+0xe2/0x630 mm/rmap.c:361
>  dup_mmap+0xc0f/0x14b0 kernel/fork.c:732
>  dup_mm kernel/fork.c:1694 [inline]
>  copy_mm kernel/fork.c:1743 [inline]
>  copy_process+0x6663/0x75c0 kernel/fork.c:2509
>  kernel_clone+0xeb/0x890 kernel/fork.c:2917
>  __do_sys_clone+0xba/0x100 kernel/fork.c:3060
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> page last free stack trace:
>  reset_page_owner include/linux/page_owner.h:24 [inline]
>  free_pages_prepare mm/page_alloc.c:1160 [inline]
>  free_unref_page_prepare+0x62e/0xcb0 mm/page_alloc.c:2383
>  free_unref_page+0x33/0x370 mm/page_alloc.c:2478
>  __unfreeze_partials+0x1fe/0x220 mm/slub.c:2647
>  qlink_free mm/kasan/quarantine.c:166 [inline]
>  qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:185
>  kasan_quarantine_reduce+0x195/0x220 mm/kasan/quarantine.c:292
>  __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305
>  kasan_slab_alloc include/linux/kasan.h:186 [inline]
>  slab_post_alloc_hook mm/slab.h:762 [inline]
>  slab_alloc_node mm/slub.c:3470 [inline]
>  slab_alloc mm/slub.c:3478 [inline]
>  __kmem_cache_alloc_lru mm/slub.c:3485 [inline]
>  kmem_cache_alloc+0x173/0x390 mm/slub.c:3494
>  getname_flags.part.0+0x50/0x4f0 fs/namei.c:140
>  getname_flags+0x9e/0xe0 include/linux/audit.h:319
>  vfs_fstatat+0x77/0xb0 fs/stat.c:275
>  __do_sys_newfstatat+0x8a/0x110 fs/stat.c:446
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
>
> Memory state around the buggy address:
>  ffff888078d2bc80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
>  ffff888078d2bd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >ffff888078d2bd80: 00 00 fc fc fc fc fc fc fc fc 00 00 00 00 00 00
>                                ^
>  ffff888078d2be00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>  ffff888078d2be80: 00 00 00 00 fc fc fc fc fc fc fc fc 00 00 00 00
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to change bug's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the bug is a duplicate of another bug, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
>