From: Jan Kara <jack@suse.cz>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-aio <linux-aio@kvack.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
syzkaller <syzkaller@googlegroups.com>,
Kostya Serebryany <kcc@google.com>,
Alexander Potapenko <glider@google.com>,
Sasha Levin <sasha.levin@oracle.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>
Subject: Re: int overflow in io_getevents
Date: Wed, 16 Dec 2015 13:56:18 +0100 [thread overview]
Message-ID: <20151216125618.GA16918@quack.suse.cz> (raw)
In-Reply-To: <CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com>
On Mon 07-12-15 11:27:07, Dmitry Vyukov wrote:
> Hello,
>
> While running syzkaller fuzzer on commit
> 31ade3b83e1821da5fbb2f11b5b3d4ab2ec39db8, I've hit the following UBSAN
> warning. I think it can lead to an unexpected active wait loop, if
> user-space expects such io_getevents to wait for a long duration but
> instead it returns immediately, so user-space reissues the same call
> again and again. Andrey suggested that read_events should validate
> timeout with timespec_valid_strict before using it.
Yup, looks correct. Will you send a patch?
Honza
> UBSAN: Undefined behaviour in include/linux/ktime.h:55:49
> signed integer overflow:
> 1449363382000000000 + 8584381026499825158 cannot be represented in
> type 'long long int'
> CPU: 0 PID: 27992 Comm: syzkaller_execu Not tainted 4.4.0-rc3+ #150
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> 0000000000000000 ffff880062ab7ae0 ffffffff82c6f2a8 0000000041b58ab3
> ffffffff8788bf8d ffffffff82c6f1f6 ffff880062ab7aa8 ffffffff88479680
> ffff880062ab7be0 7721d90fc5200e06 0000000000000001 ffff880062ab7af0
> Call Trace:
> [< inline >] __dump_stack lib/dump_stack.c:15
> [<ffffffff82c6f2a8>] dump_stack+0xb2/0xfa lib/dump_stack.c:50
> [<ffffffff82d622e7>] ubsan_epilogue+0x12/0x8f lib/ubsan.c:160
> [<ffffffff82d63e58>] handle_overflow+0x22f/0x276 lib/ubsan.c:191
> [<ffffffff82d63ec9>] __ubsan_handle_add_overflow+0x2a/0x31 lib/ubsan.c:199
> [< inline >] ktime_set include/linux/ktime.h:55
> [< inline >] timespec_to_ktime include/linux/ktime.h:83
> [<ffffffff8190ca77>] read_events+0x4b7/0x560 fs/aio.c:1273
> [< inline >] SYSC_io_getevents fs/aio.c:1737
> [<ffffffff81913567>] SyS_io_getevents+0xc7/0x340 fs/aio.c:1726
> [<ffffffff868dae76>] entry_SYSCALL_64_fastpath+0x16/0x7a
> arch/x86/entry/entry_64.S:185
>
> Thank you
> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2015-12-16 12:56 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-07 10:27 int overflow in io_getevents Dmitry Vyukov
2015-12-16 12:56 ` Jan Kara [this message]
2015-12-16 18:38 ` Dmitry Vyukov
2015-12-18 8:15 ` Jan Kara
2016-01-06 18:01 ` Benjamin LaHaise
2016-01-07 9:12 ` Dmitry Vyukov
2016-01-07 15:31 ` Benjamin LaHaise
2016-01-07 15:37 ` Dmitry Vyukov
2016-01-07 15:52 ` Benjamin LaHaise
2016-01-07 16:27 ` Dmitry Vyukov
2016-10-26 11:44 ` Jiri Slaby
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=20151216125618.GA16918@quack.suse.cz \
--to=jack@suse.cz \
--cc=bcrl@kvack.org \
--cc=dvyukov@google.com \
--cc=glider@google.com \
--cc=kcc@google.com \
--cc=linux-aio@kvack.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ryabinin.a.a@gmail.com \
--cc=sasha.levin@oracle.com \
--cc=syzkaller@googlegroups.com \
--cc=viro@zeniv.linux.org.uk \
/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;
as well as URLs for NNTP newsgroup(s).