From: Benjamin LaHaise <bcrl@kvack.org>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: Jan Kara <jack@suse.cz>, 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: Thu, 7 Jan 2016 10:31:32 -0500 [thread overview]
Message-ID: <20160107153132.GL4439@kvack.org> (raw)
In-Reply-To: <CACT4Y+YqGRmXN47A3kcX-KKggyP04Ljfe_PXHyV48mAOgq8i-A@mail.gmail.com>
On Thu, Jan 07, 2016 at 10:12:02AM +0100, Dmitry Vyukov wrote:
...
> Sorry, but the following program still prints -9223372036562067969. I
> think timespec_valid check will do.
Ah, right. Yes, using timespec_valid() instead of timespec_valid_strict()
as initially proposed will address my concerns. Updated commit below.
-ben
--
"Thought is the essence of where you are now."
commit 3a55c535cf3836257434518bd6bc11464c493492
Author: Benjamin LaHaise <bcrl@kvack.org>
Date: Thu Jan 7 10:25:44 2016 -0500
aio: handle integer overflow in io_getevents() timespec usage
Dmitry Vyukov reported an integer overflow in io_getevents() when
running a fuzzer. Upon investigation, the triggers appears to be that
an invalid value for the tv_sec or tv_nsec was passed in which is not
handled by timespec_to_ktime(). This patch fixes that by making
io_getevents() return -EINVAL when timespec_valid() checks fail. We
use timespec_valid() instead of timespec_valid_strict() to avoid issues
caused by userspace not knowing the cutoff for KTIME_SEC_MAX.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
diff --git a/fs/aio.c b/fs/aio.c
index 155f842..d161a2f 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1269,6 +1269,8 @@ static long read_events(struct kioctx *ctx, long min_nr, long nr,
if (unlikely(copy_from_user(&ts, timeout, sizeof(ts))))
return -EFAULT;
+ if (!timespec_valid())
+ return -EINVAL;
until = timespec_to_ktime(ts);
}
next prev parent reply other threads:[~2016-01-07 15:31 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
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 [this message]
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
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