All of lore.kernel.org
 help / color / mirror / Atom feed
From: syzbot <syzbot+b90df26038d1d5d85c97@syzkaller.appspotmail.com>
To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, syzkaller-bugs@googlegroups.com
Subject: KASAN: use-after-free Read in do_madvise
Date: Fri, 21 Aug 2020 09:58:20 -0700	[thread overview]
Message-ID: <000000000000e44b7d05ad6624df@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    da2968ff Merge tag 'pci-v5.9-fixes-1' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1339995a900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a0437fdd630bee11
dashboard link: https://syzkaller.appspot.com/bug?extid=b90df26038d1d5d85c97
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1225d919900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b90df26038d1d5d85c97@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in madvise_willneed mm/madvise.c:293 [inline]
BUG: KASAN: use-after-free in madvise_vma mm/madvise.c:942 [inline]
BUG: KASAN: use-after-free in do_madvise.part.0+0x1c8b/0x1cf0 mm/madvise.c:1145
Read of size 8 at addr ffff8880a6163eb0 by task syz-executor.0/9996

CPU: 0 PID: 9996 Comm: syz-executor.0 Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 madvise_willneed mm/madvise.c:293 [inline]
 madvise_vma mm/madvise.c:942 [inline]
 do_madvise.part.0+0x1c8b/0x1cf0 mm/madvise.c:1145
 do_madvise mm/madvise.c:1169 [inline]
 __do_sys_madvise mm/madvise.c:1171 [inline]
 __se_sys_madvise mm/madvise.c:1169 [inline]
 __x64_sys_madvise+0xd9/0x110 mm/madvise.c:1169
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d4d9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f04f7464c78 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 0000000000020800 RCX: 000000000045d4d9
RDX: 0000000000000003 RSI: 0000000000600003 RDI: 0000000020000000
RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffc579cce7f R14: 00007f04f74659c0 R15: 000000000118cfec

Allocated by task 9992:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 slab_post_alloc_hook mm/slab.h:518 [inline]
 slab_alloc mm/slab.c:3312 [inline]
 kmem_cache_alloc+0x138/0x3a0 mm/slab.c:3482
 vm_area_alloc+0x1c/0x110 kernel/fork.c:347
 mmap_region+0x8e5/0x1780 mm/mmap.c:1743
 do_mmap+0xcf9/0x11d0 mm/mmap.c:1545
 vm_mmap_pgoff+0x195/0x200 mm/util.c:506
 ksys_mmap_pgoff+0x43a/0x560 mm/mmap.c:1596
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 9992:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
 __cache_free mm/slab.c:3418 [inline]
 kmem_cache_free.part.0+0x67/0x1f0 mm/slab.c:3693
 remove_vma+0x132/0x170 mm/mmap.c:184
 remove_vma_list mm/mmap.c:2613 [inline]
 __do_munmap+0x743/0x1170 mm/mmap.c:2869
 do_munmap mm/mmap.c:2877 [inline]
 mmap_region+0x257/0x1780 mm/mmap.c:1716
 do_mmap+0xcf9/0x11d0 mm/mmap.c:1545
 vm_mmap_pgoff+0x195/0x200 mm/util.c:506
 ksys_mmap_pgoff+0x43a/0x560 mm/mmap.c:1596
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880a6163eb0
 which belongs to the cache vm_area_struct of size 200
The buggy address is located 0 bytes inside of
 200-byte region [ffff8880a6163eb0, ffff8880a6163f78)
The buggy address belongs to the page:
page:00000000dc1e014c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa6163
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002494bc8 ffffea0002a5ad88 ffff8880aa06f500
raw: 0000000000000000 ffff8880a6163040 000000010000000f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a6163d80: fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a6163e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc
>ffff8880a6163e80: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880a6163f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
 ffff8880a6163f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

             reply	other threads:[~2020-08-21 17:03 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-21 16:58 syzbot [this message]
2020-08-21 17:15 ` KASAN: use-after-free Read in do_madvise Yang Shi
2020-08-21 20:03   ` Andrew Morton
2020-08-21 20:34     ` Yang Shi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=000000000000e44b7d05ad6624df@google.com \
    --to=syzbot+b90df26038d1d5d85c97@syzkaller.appspotmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=syzkaller-bugs@googlegroups.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.