From: Stefano Brivio <sbrivio@redhat.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
Lorenzo Colitti <lorenzo@google.com>
Subject: Re: Use after free in __dst_destroy_metrics_generic
Date: Fri, 8 Sep 2017 18:17:00 +0200 [thread overview]
Message-ID: <20170908181700.2ef9d31c@elisabeth> (raw)
In-Reply-To: <CAM_iQpV--V9ROSd61CWVbcpCHonMUubLeyEKVSvEUTTW3gh5hA@mail.gmail.com>
On Fri, 8 Sep 2017 09:12:09 -0700
Cong Wang <xiyou.wangcong@gmail.com> wrote:
> On Thu, Sep 7, 2017 at 5:56 PM, Stefano Brivio <sbrivio@redhat.com> wrote:
> > On Thu, 07 Sep 2017 18:52:02 -0600
> > Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> wrote:
> >
> >> We are seeing a possible use after free in ip6_dst_destroy.
> >>
> >> It appears as if memory of the __DST_METRICS_PTR(old) was freed in some
> >> path and allocated
> >> to ion driver. ion driver has also freed it. Finally the memory is freed
> >> by the
> >> fib gc and crashes since it is already deallocated.
> >>
> >> Target is running an ARM64 Android based 4.9 kernel.
> >> Issue was seen once on a regression rack (sorry, no reproducer).
> >> Any pointers to debug this is highly appreciated.
> >>
> >> [ 3489.470581] [<ffffff83c0a289c0>] object_err+0x4c/0x5c
> >> [ 3489.470586] [<ffffff83c0a2b284>] free_debug_processing+0x2e0/0x398
> >> [ 3489.470589] [<ffffff83c0a2b63c>] __slab_free+0x300/0x3e0
> >> [ 3489.470593] [<ffffff83c0a2bfc8>] kfree+0x28c/0x290
> >> [ 3489.470601] [<ffffff83c16b9580>]
> >> __dst_destroy_metrics_generic+0x6c/0x78
> >> [ 3489.470609] [<ffffff83c17d3408>] ip6_dst_destroy+0xb0/0xb4
> >
> > Should be fixed by:
> >
> > commit ad65a2f05695aced349e308193c6e2a6b1d87112
> > Author: Wei Wang <weiwan@google.com>
> > Date: Sat Jun 17 10:42:35 2017 -0700
> >
> > ipv6: call dst_hold_safe() properly
>
> Obviously it should not. One is dst metric, the other is dst.
And obviously you're right. Sorry for the confusion, I blatantly
misread the backtrace.
next prev parent reply other threads:[~2017-09-08 16:17 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-08 0:52 Use after free in __dst_destroy_metrics_generic Subash Abhinov Kasiviswanathan
2017-09-08 0:56 ` Stefano Brivio
2017-09-08 1:33 ` Subash Abhinov Kasiviswanathan
2017-09-08 16:12 ` Cong Wang
2017-09-08 16:17 ` Stefano Brivio [this message]
2017-09-08 2:13 ` David Miller
2017-09-08 3:27 ` Subash Abhinov Kasiviswanathan
2017-09-08 16:10 ` Cong Wang
2017-09-08 17:16 ` Eric Dumazet
2017-09-08 17:19 ` David Miller
2017-09-08 17:28 ` Eric Dumazet
2017-09-08 19:50 ` Subash Abhinov Kasiviswanathan
2017-09-15 21:00 ` Eric Dumazet
2017-09-15 22:38 ` Julian Anastasov
2017-09-15 23:20 ` Subash Abhinov Kasiviswanathan
2017-09-16 12:40 ` Julian Anastasov
2017-09-16 18:21 ` Cong Wang
2017-09-16 18:13 ` Cong Wang
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