From: Eric Biggers <ebiggers3@gmail.com>
To: syzbot
<bot+d10271989aa91b0c140f6c218c5537f942888ce2@syzkaller.appspotmail.com>
Cc: danielj@mellanox.com, dledford@redhat.com, eparis@parisplace.org,
james.l.morris@oracle.com, junil0814.lee@lge.com,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org, mka@chromium.org,
paul@paul-moore.com, sds@tycho.nsa.gov, selinux@tycho.nsa.gov,
serge@hallyn.com, syzkaller-bugs@googlegroups.com
Subject: Re: BUG: unable to handle kernel paging request in security_compute_sid
Date: Fri, 22 Dec 2017 16:14:39 -0600 [thread overview]
Message-ID: <20171222221439.GA28786@zzz.localdomain> (raw)
In-Reply-To: <001a113f9ae0812d650560f4a1d6@google.com>
On Fri, Dec 22, 2017 at 01:38:01PM -0800, syzbot wrote:
> Hello,
>
> syzkaller hit the following crash on
> 6084b576dca2e898f5c101baef151f7bfdbb606d
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> C reproducer is attached
> syzkaller reproducer is attached. See https://goo.gl/kgGztJ
> for information about syzkaller reproducers
>
>
> BUG: unable to handle kernel paging request at 00000000830e2118
> IP: security_compute_sid.part.11+0x418/0x710
> security/selinux/ss/services.c:1640
> PGD 0 P4D 0
> Oops: 0000 [#1] SMP
> Dumping ftrace buffer:
> (ftrace buffer empty)
> Modules linked in:
> CPU: 0 PID: 3391 Comm: kworker/u4:0 Not tainted 4.15.0-rc3-next-20171214+
> #67
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> RIP: 0010:security_compute_sid.part.11+0x418/0x710
> security/selinux/ss/services.c:1640
> RSP: 0018:ffffc90001993c70 EFLAGS: 00010293
> RAX: ffff880216ba0800 RBX: 0000000000000002 RCX: ffffffff81667b88
> RDX: 0000000000000000 RSI: 0000000000000005 RDI: ffffffff83fd17a0
> RBP: ffffc90001993d20 R08: 0000000000000001 R09: 0000000000000001
> R10: ffffc90001993be0 R11: 0000000000000000 R12: ffff88021694f188
> R13: 0000000000000010 R14: ffff880216592388 R15: 00000000830e20e0
> FS: 0000000000000000(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00000000830e2118 CR3: 000000000301e001 CR4: 00000000001606f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> security_compute_sid+0x92/0xa0 security/selinux/ss/services.c:1598
> security_transition_sid+0x57/0x70 security/selinux/ss/services.c:1764
> selinux_bprm_set_creds+0x215/0x2f0 security/selinux/hooks.c:2423
> security_bprm_set_creds+0x41/0x60 security/security.c:332
> prepare_binprm+0xae/0x1f0 fs/exec.c:1561
> do_execveat_common.isra.30+0x6f7/0xb90 fs/exec.c:1784
> do_execve+0x31/0x40 fs/exec.c:1848
> call_usermodehelper_exec_async+0x104/0x190 kernel/umh.c:100
> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524
> Code: 40 74 15 41 83 fd 10 74 0f e8 d5 27 c5 ff 4d 85 ff 75 33 e9 6f 02 00
> 00 e8 c6 27 c5 ff 4d 85 ff 0f 84 e6 02 00 00 e8 b8 27 c5 ff <41> 80 7f 38 02
> 0f 84 5c 01 00 00 e8 a8 27 c5 ff 41 8b 06 89 45
> RIP: security_compute_sid.part.11+0x418/0x710
> security/selinux/ss/services.c:1640 RSP: ffffc90001993c70
> CR2: 00000000830e2118
> ---[ end trace fe59d8175af57ffc ]---
> Kernel panic - not syncing: Fatal exception
> Dumping ftrace buffer:
> (ftrace buffer empty)
> Kernel Offset: disabled
> Rebooting in 86400 seconds..
>
This is yet another one where the reproducer is using AF_ALG and binding to the
"pcrypt(gcm_base(ctr(aes-aesni),ghash-generic))" algorithm, so it's running into
the pcrypt_free() bug which is causing slab cache corruption:
https://groups.google.com/forum/#!topic/syzkaller-bugs/NKn_ivoPOpk
https://patchwork.kernel.org/patch/10126761/
So let's mark it as a duplicate:
#syz dup: KASAN: use-after-free Read in __list_del_entry_valid (2)
I wonder if it would be of any help to disable slab cache merging, i.e. set
CONFIG_SLAB_MERGE_DEFAULT=n? That would reduce the number of duplicate reports,
though perhaps at the risk of hiding bugs.
Eric
next prev parent reply other threads:[~2017-12-22 22:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-22 21:38 syzbot
2017-12-22 22:14 ` Eric Biggers [this message]
2017-12-23 11:44 ` Dmitry Vyukov
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=20171222221439.GA28786@zzz.localdomain \
--to=ebiggers3@gmail.com \
--cc=bot+d10271989aa91b0c140f6c218c5537f942888ce2@syzkaller.appspotmail.com \
--cc=danielj@mellanox.com \
--cc=dledford@redhat.com \
--cc=eparis@parisplace.org \
--cc=james.l.morris@oracle.com \
--cc=junil0814.lee@lge.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mka@chromium.org \
--cc=paul@paul-moore.com \
--cc=sds@tycho.nsa.gov \
--cc=selinux@tycho.nsa.gov \
--cc=serge@hallyn.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®