From: Eric Biggers <ebiggers3@gmail.com>
To: syzbot <syzbot+8a608baf8751184ec727@syzkaller.appspotmail.com>
Cc: davem@davemloft.net, herbert@gondor.apana.org.au,
linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com
Subject: Re: KASAN: slab-out-of-bounds Write in sha256_final
Date: Thu, 7 Jun 2018 12:17:35 -0700 [thread overview]
Message-ID: <20180607191735.GB29665@gmail.com> (raw)
In-Reply-To: <00000000000079e595056e0d0796@google.com>
On Thu, Jun 07, 2018 at 06:12:02AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 1c8c5a9d38f6 Merge git://git.kernel.org/pub/scm/linux/kern..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=12cca2af800000
> kernel config: https://syzkaller.appspot.com/x/.config?x=2e1a31e8576e013a
> dashboard link: https://syzkaller.appspot.com/bug?extid=8a608baf8751184ec727
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+8a608baf8751184ec727@syzkaller.appspotmail.com
>
> ==================================================================
> BUG: KASAN: slab-out-of-bounds in put_unaligned_be32
> include/linux/unaligned/access_ok.h:60 [inline]
> BUG: KASAN: slab-out-of-bounds in sha256_base_finish
> include/crypto/sha256_base.h:124 [inline]
> BUG: KASAN: slab-out-of-bounds in sha256_final+0x303/0x380
> crypto/sha256_generic.c:253
> Write of size 4 at addr ffff8801ce26f060 by task syz-executor1/7811
>
> CPU: 0 PID: 7811 Comm: syz-executor1 Not tainted 4.17.0+ #88
> 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+0x1b9/0x294 lib/dump_stack.c:113
> print_address_description+0x6c/0x20b mm/kasan/report.c:256
> kasan_report_error mm/kasan/report.c:354 [inline]
> kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
> __asan_report_store4_noabort+0x17/0x20 mm/kasan/report.c:437
> put_unaligned_be32 include/linux/unaligned/access_ok.h:60 [inline]
> sha256_base_finish include/crypto/sha256_base.h:124 [inline]
> sha256_final+0x303/0x380 crypto/sha256_generic.c:253
> crypto_shash_final+0x104/0x260 crypto/shash.c:152
> kdf_ctr security/keys/dh.c:186 [inline]
> keyctl_dh_compute_kdf security/keys/dh.c:217 [inline]
> __keyctl_dh_compute+0x1184/0x1bc0 security/keys/dh.c:389
> keyctl_dh_compute+0xb9/0x100 security/keys/dh.c:425
> __do_sys_keyctl security/keys/keyctl.c:1741 [inline]
> __se_sys_keyctl security/keys/keyctl.c:1637 [inline]
> __x64_sys_keyctl+0x12a/0x3b0 security/keys/keyctl.c:1637
> do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x455a09
> Code: 1d ba 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 eb b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007fc9dbbc5c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000fa
> RAX: ffffffffffffffda RBX: 00007fc9dbbc66d4 RCX: 0000000000455a09
> RDX: 0000000020000080 RSI: 00000000200001c0 RDI: 0000000000000017
> RBP: 000000000072bea0 R08: 0000000020000200 R09: 0000000000000000
> R10: 0000000000000005 R11: 0000000000000246 R12: 00000000ffffffff
> R13: 0000000000000499 R14: 00000000006fbef8 R15: 0000000000000000
>
> Allocated by task 7811:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:448
> set_track mm/kasan/kasan.c:460 [inline]
> kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
> __do_kmalloc mm/slab.c:3718 [inline]
> __kmalloc+0x14e/0x760 mm/slab.c:3727
> kmalloc include/linux/slab.h:518 [inline]
> keyctl_dh_compute_kdf security/keys/dh.c:211 [inline]
> __keyctl_dh_compute+0xfe9/0x1bc0 security/keys/dh.c:389
> keyctl_dh_compute+0xb9/0x100 security/keys/dh.c:425
> __do_sys_keyctl security/keys/keyctl.c:1741 [inline]
> __se_sys_keyctl security/keys/keyctl.c:1637 [inline]
> __x64_sys_keyctl+0x12a/0x3b0 security/keys/keyctl.c:1637
> do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> Freed by task 2819:
> save_stack+0x43/0xd0 mm/kasan/kasan.c:448
> set_track mm/kasan/kasan.c:460 [inline]
> __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
> kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
> __cache_free mm/slab.c:3498 [inline]
> kfree+0xd9/0x260 mm/slab.c:3813
> single_release+0x8f/0xb0 fs/seq_file.c:609
> __fput+0x353/0x890 fs/file_table.c:209
> ____fput+0x15/0x20 fs/file_table.c:243
> task_work_run+0x1e4/0x290 kernel/task_work.c:113
> tracehook_notify_resume include/linux/tracehook.h:192 [inline]
> exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166
> prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
> syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
> do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> The buggy address belongs to the object at ffff8801ce26f040
> which belongs to the cache kmalloc-32 of size 32
> The buggy address is located 0 bytes to the right of
> 32-byte region [ffff8801ce26f040, ffff8801ce26f060)
> The buggy address belongs to the page:
> page:ffffea0007389bc0 count:1 mapcount:0 mapping:ffff8801ce26f000
> index:0xffff8801ce26ffc1
> flags: 0x2fffc0000000100(slab)
> raw: 02fffc0000000100 ffff8801ce26f000 ffff8801ce26ffc1 000000010000003f
> raw: ffffea000739d360 ffff8801da801248 ffff8801da8001c0 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff8801ce26ef00: 00 fc fc 00 00 00 00 00 fc fc 00 00 00 00 00 fc
> ffff8801ce26ef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> > ffff8801ce26f000: fb fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
> ^
> ffff8801ce26f080: 05 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
> ffff8801ce26f100: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
> ==================================================================
>
>
> ---
> This bug 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 bug report. See:
> https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
> syzbot.
>
Duplicate:
#syz dup: KASAN: slab-out-of-bounds Write in sha1_finup
Tentative fix is "[PATCH] dh key: fix rounding up KDF output length".
prev parent reply other threads:[~2018-06-07 19:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-07 13:12 KASAN: slab-out-of-bounds Write in sha256_final syzbot
2018-06-07 15:11 ` syzbot
2018-06-07 19:17 ` Eric Biggers [this message]
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=20180607191735.GB29665@gmail.com \
--to=ebiggers3@gmail.com \
--cc=davem@davemloft.net \
--cc=herbert@gondor.apana.org.au \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=syzbot+8a608baf8751184ec727@syzkaller.appspotmail.com \
--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.