Re: general protection fault in inet_unhash
On 5/29/20 10:32 AM, Eric Dumazet wrote:
On 5/28/20 11:32 PM, Andrii Nakryiko wrote:
On 5/28/20 11:23 PM, Dmitry Vyukov wrote:
On Thu, May 28, 2020 at 11:01 PM 'Andrii Nakryiko' via syzkaller-bugs
wrote:
On 5/28/20 9:44 AM, syzbot wrote:
Hello,
syzbot found the following crash on:
HEAD commit: dc0f3ed1 net: phy: at803x: add cable diagnostics support f..
git tree: net-next
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D17289cd210&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=t1v5ZakZM9Aw_9u_I6FbFZ28U0GFs0e9dMMUOyiDxO4&e=
kernel config:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3D7e1bc97341edbea6&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=yeXCTODuJF6ExmCJ-ppqMHsfvMCbCQ9zkmZi3W6NGHo&e=
dashboard link:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3D3610d489778b57cc8031&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=8fAJHh81yojiinnGJzTw6hN4w4A6XRZST4463CWL9Y8&e=
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D15f237aa10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=cPv-hQsGYs0CVz3I26BmauS0hQ8_YTWHeH5p-U5ElWY&e=
C reproducer:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D1553834a10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=r6sGJDOgosZDE9sRxqFnVibDNJFt_6IteSWeqEQLbNE&e=
The bug was bisected to:
commit af6eea57437a830293eab56246b6025cc7d46ee7
Author: Andrii Nakryiko
Date: Mon Mar 30 02:59:58 2020 +
bpf: Implement bpf_link-based cgroup BPF program attachment
bisection log:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_bisect.txt-3Fx-3D1173cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=rJIpYFSAMRfea3349dd7PhmLD_hriVwq8ZtTHcSagBA&e=
final crash:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_report.txt-3Fx-3D1373cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=TWpx5JNdxKiKPABUScn8WB7u3fXueCp7BXwQHg4Unz0&e=
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D1573cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=-SMhn-dVZI4W51EZQ8Im0sdThgwt9M6fxUt3_bcYvk8&e=
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3610d489778b57cc8...@syzkaller.appspotmail.com
Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program
attachment")
general protection fault, probably for non-canonical address
0xdc01: [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0008-0x000f]
CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
01/01/2011
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
No idea why it was bisected to bpf_link change. It seems completely
struct sock-related. Seems like
Hi Andrii,
You can always find a detailed explanation of syzbot bisections under
the "bisection log" link.
Right. Sorry, I didn't mean that bisect went wrong or anything like that. I
just don't see how my change has anything to do with invalid socket state. As I
just replied in another email, this particular repro is using bpf_link_create()
for cgroup attachment, which was added in my patch. So running repro before my
patch would always fail to attach BPF program, and thus won't be able to repro
the issue (because the bug is somewhere in the interaction between BPF program
attachment and socket itself). So it will always bisect to my patch :)
L2TP seems to use sk->sk_node to insert sockets into l2tp_ip_table, _and_ uses
l2tp_ip_prot.unhash == inet_unhash
So if/when BPF_CGROUP_RUN_PROG_INET_SOCK(sk) returns an error and inet_create()
calls sk_common_release()
bad things happen, because inet_unhash() expects a valid hashinfo pointer.
I guess the following patch should fix this.
Bug has been there forever, but only BPF_CGROUP_RUN_PROG_INET_SOCK(sk) could
trigger it.
I knew it! :) Thanks a lot for taking a look, Eric!
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index
10cf7c3dcbb3fb1b27657588f3d1ba806cba737f..097c80c0e323777df997a189eb456e3ae6d26888
100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@
Re: general protection fault in inet_unhash
On 5/29/20 10:32 AM, Eric Dumazet wrote: > L2TP seems to use sk->sk_node to insert sockets into l2tp_ip_table, _and_ > uses l2tp_ip_prot.unhash == inet_unhash > > So if/when BPF_CGROUP_RUN_PROG_INET_SOCK(sk) returns an error and > inet_create() calls sk_common_release() > bad things happen, because inet_unhash() expects a valid hashinfo pointer. > > I guess the following patch should fix this. > > Bug has been there forever, but only BPF_CGROUP_RUN_PROG_INET_SOCK(sk) could > trigger it. > Official submission : https://patchwork.ozlabs.org/project/netdev/patch/20200529180838.107255-1-eduma...@google.com/
Re: general protection fault in inet_unhash
On 5/28/20 11:32 PM, Andrii Nakryiko wrote:
> On 5/28/20 11:23 PM, Dmitry Vyukov wrote:
>> On Thu, May 28, 2020 at 11:01 PM 'Andrii Nakryiko' via syzkaller-bugs
>> wrote:
>>>
>>> On 5/28/20 9:44 AM, syzbot wrote:
Hello,
syzbot found the following crash on:
HEAD commit: dc0f3ed1 net: phy: at803x: add cable diagnostics support
f..
git tree: net-next
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D17289cd210&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=t1v5ZakZM9Aw_9u_I6FbFZ28U0GFs0e9dMMUOyiDxO4&e=
kernel config:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3D7e1bc97341edbea6&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=yeXCTODuJF6ExmCJ-ppqMHsfvMCbCQ9zkmZi3W6NGHo&e=
dashboard link:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3D3610d489778b57cc8031&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=8fAJHh81yojiinnGJzTw6hN4w4A6XRZST4463CWL9Y8&e=
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D15f237aa10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=cPv-hQsGYs0CVz3I26BmauS0hQ8_YTWHeH5p-U5ElWY&e=
C reproducer:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D1553834a10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=r6sGJDOgosZDE9sRxqFnVibDNJFt_6IteSWeqEQLbNE&e=
The bug was bisected to:
commit af6eea57437a830293eab56246b6025cc7d46ee7
Author: Andrii Nakryiko
Date: Mon Mar 30 02:59:58 2020 +
bpf: Implement bpf_link-based cgroup BPF program attachment
bisection log:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_bisect.txt-3Fx-3D1173cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=rJIpYFSAMRfea3349dd7PhmLD_hriVwq8ZtTHcSagBA&e=
final crash:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_report.txt-3Fx-3D1373cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=TWpx5JNdxKiKPABUScn8WB7u3fXueCp7BXwQHg4Unz0&e=
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D1573cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=-SMhn-dVZI4W51EZQ8Im0sdThgwt9M6fxUt3_bcYvk8&e=
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3610d489778b57cc8...@syzkaller.appspotmail.com
Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program
attachment")
general protection fault, probably for non-canonical address
0xdc01: [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0008-0x000f]
CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
>>>
>>> No idea why it was bisected to bpf_link change. It seems completely
>>> struct sock-related. Seems like
>>
>> Hi Andrii,
>>
>> You can always find a detailed explanation of syzbot bisections under
>> the "bisection log" link.
>
> Right. Sorry, I didn't mean that bisect went wrong or anything like that. I
> just don't see how my change has anything to do with invalid socket state. As
> I just replied in another email, this particular repro is using
> bpf_link_create() for cgroup attachment, which was added in my patch. So
> running repro before my patch would always fail to attach BPF program, and
> thus won't be able to repro the issue (because the bug is somewhere in the
> interaction between BPF program attachment and socket itself). So it will
> always bisect to my patch :)
L2TP seems to use sk->sk_node to insert sockets into l2tp_ip_table, _and_ uses
l2tp_ip_prot.unhash == inet_unhash
So if/when BPF_CGROUP_RUN_PROG_INET_SOCK(sk) returns an error and inet_create()
calls sk_common_release()
bad things happen, because inet_unhash() expects a valid hashinfo pointer.
I guess the following patch should fix this.
Bug has been there forever, but only BPF_CGROUP_RUN_PROG_INET_SOCK(sk) could
trigger it.
diff --git a/net/l2tp/l2tp_core.h b/n
Re: general protection fault in inet_unhash
On Fri, May 29, 2020 at 8:33 AM Andrii Nakryiko wrote:
>
> On 5/28/20 11:23 PM, Dmitry Vyukov wrote:
> > On Thu, May 28, 2020 at 11:01 PM 'Andrii Nakryiko' via syzkaller-bugs
> > wrote:
> >>
> >> On 5/28/20 9:44 AM, syzbot wrote:
> >>> Hello,
> >>>
> >>> syzbot found the following crash on:
> >>>
> >>> HEAD commit:dc0f3ed1 net: phy: at803x: add cable diagnostics support
> >>> f..
> >>> git tree: net-next
> >>> console output:
> >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D17289cd210&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=t1v5ZakZM9Aw_9u_I6FbFZ28U0GFs0e9dMMUOyiDxO4&e=
> >>> kernel config:
> >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3D7e1bc97341edbea6&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=yeXCTODuJF6ExmCJ-ppqMHsfvMCbCQ9zkmZi3W6NGHo&e=
> >>> dashboard link:
> >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3D3610d489778b57cc8031&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=8fAJHh81yojiinnGJzTw6hN4w4A6XRZST4463CWL9Y8&e=
> >>> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> >>> syz repro:
> >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D15f237aa10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=cPv-hQsGYs0CVz3I26BmauS0hQ8_YTWHeH5p-U5ElWY&e=
> >>> C reproducer:
> >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D1553834a10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=r6sGJDOgosZDE9sRxqFnVibDNJFt_6IteSWeqEQLbNE&e=
> >>>
> >>> The bug was bisected to:
> >>>
> >>> commit af6eea57437a830293eab56246b6025cc7d46ee7
> >>> Author: Andrii Nakryiko
> >>> Date: Mon Mar 30 02:59:58 2020 +
> >>>
> >>> bpf: Implement bpf_link-based cgroup BPF program attachment
> >>>
> >>> bisection log:
> >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_bisect.txt-3Fx-3D1173cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=rJIpYFSAMRfea3349dd7PhmLD_hriVwq8ZtTHcSagBA&e=
> >>> final crash:
> >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_report.txt-3Fx-3D1373cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=TWpx5JNdxKiKPABUScn8WB7u3fXueCp7BXwQHg4Unz0&e=
> >>> console output:
> >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D1573cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=-SMhn-dVZI4W51EZQ8Im0sdThgwt9M6fxUt3_bcYvk8&e=
> >>>
> >>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> >>> Reported-by: syzbot+3610d489778b57cc8...@syzkaller.appspotmail.com
> >>> Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program
> >>> attachment")
> >>>
> >>> general protection fault, probably for non-canonical address
> >>> 0xdc01: [#1] PREEMPT SMP KASAN
> >>> KASAN: null-ptr-deref in range [0x0008-0x000f]
> >>> CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
> >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> >>> Google 01/01/2011
> >>> RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
> >>
> >> No idea why it was bisected to bpf_link change. It seems completely
> >> struct sock-related. Seems like
> >
> > Hi Andrii,
> >
> > You can always find a detailed explanation of syzbot bisections under
> > the "bisection log" link.
>
> Right. Sorry, I didn't mean that bisect went wrong or anything like
> that. I just don't see how my change has anything to do with invalid
> socket state. As I just replied in another email, this particular repro
> is using bpf_link_create() for cgroup attachment, which was added in my
> patch. So running repro before my patch would always fail to attach BPF
> program, and thus won't be able to repro the issue (because the bug is
> somewhere in the interaction between BPF program attachment and socket
> itself). So it will always bisect to my patch :)
This happens sometimes. Sometimes bugs are bisected to the addition of
the debug check/tool. Which is... kinda working as intended. There is
only that much we can ask from the robot.
> >> struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
> >>
> >> ends up being NULL.
> >>
> >> Can some more networking-savvy people help with investigating this, please?
> >>
> >>> Code: 03 0f b6 04 02 84 c0 74 08 3c 03
Re: general protection fault in inet_unhash
On 5/28/20 11:23 PM, Dmitry Vyukov wrote:
On Thu, May 28, 2020 at 11:01 PM 'Andrii Nakryiko' via syzkaller-bugs
wrote:
On 5/28/20 9:44 AM, syzbot wrote:
Hello,
syzbot found the following crash on:
HEAD commit:dc0f3ed1 net: phy: at803x: add cable diagnostics support f..
git tree: net-next
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D17289cd210&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=t1v5ZakZM9Aw_9u_I6FbFZ28U0GFs0e9dMMUOyiDxO4&e=
kernel config:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3D7e1bc97341edbea6&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=yeXCTODuJF6ExmCJ-ppqMHsfvMCbCQ9zkmZi3W6NGHo&e=
dashboard link:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3D3610d489778b57cc8031&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=8fAJHh81yojiinnGJzTw6hN4w4A6XRZST4463CWL9Y8&e=
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D15f237aa10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=cPv-hQsGYs0CVz3I26BmauS0hQ8_YTWHeH5p-U5ElWY&e=
C reproducer:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D1553834a10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=r6sGJDOgosZDE9sRxqFnVibDNJFt_6IteSWeqEQLbNE&e=
The bug was bisected to:
commit af6eea57437a830293eab56246b6025cc7d46ee7
Author: Andrii Nakryiko
Date: Mon Mar 30 02:59:58 2020 +
bpf: Implement bpf_link-based cgroup BPF program attachment
bisection log:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_bisect.txt-3Fx-3D1173cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=rJIpYFSAMRfea3349dd7PhmLD_hriVwq8ZtTHcSagBA&e=
final crash:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_report.txt-3Fx-3D1373cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=TWpx5JNdxKiKPABUScn8WB7u3fXueCp7BXwQHg4Unz0&e=
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D1573cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=-SMhn-dVZI4W51EZQ8Im0sdThgwt9M6fxUt3_bcYvk8&e=
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3610d489778b57cc8...@syzkaller.appspotmail.com
Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program
attachment")
general protection fault, probably for non-canonical address
0xdc01: [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0008-0x000f]
CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
01/01/2011
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
No idea why it was bisected to bpf_link change. It seems completely
struct sock-related. Seems like
Hi Andrii,
You can always find a detailed explanation of syzbot bisections under
the "bisection log" link.
Right. Sorry, I didn't mean that bisect went wrong or anything like
that. I just don't see how my change has anything to do with invalid
socket state. As I just replied in another email, this particular repro
is using bpf_link_create() for cgroup attachment, which was added in my
patch. So running repro before my patch would always fail to attach BPF
program, and thus won't be able to repro the issue (because the bug is
somewhere in the interaction between BPF program attachment and socket
itself). So it will always bisect to my patch :)
struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
ends up being NULL.
Can some more networking-savvy people help with investigating this, please?
Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dd 04 00 00 48 8d 7d 08 44 8b 73 08 48
b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 55 05 00 00
48 8d 7d 14 4c 8b 6d 08 48 b8 00 00
RSP: 0018:c90001777d30 EFLAGS: 00010202
RAX: dc00 RBX: 88809a6df940 RCX: 8697c242
RDX: 0001 RSI: 8697c251 RDI: 0008
RBP: R08: 88809f3ae1c0 R09: fbfff1514cc1
R10: 8a8a6607 R11: fbfff1514cc0 R12: 88809a6df9b0
R13: 0007 R14: R15: 873a4d00
FS: 01d2b880() GS:8880ae60() k
Re: general protection fault in inet_unhash
On 5/28/20 2:27 PM, Eric Dumazet wrote:
On 5/28/20 2:01 PM, Andrii Nakryiko wrote:
On 5/28/20 9:44 AM, syzbot wrote:
Hello,
syzbot found the following crash on:
HEAD commit: dc0f3ed1 net: phy: at803x: add cable diagnostics support f..
git tree: net-next
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D17289cd210&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=t1v5ZakZM9Aw_9u_I6FbFZ28U0GFs0e9dMMUOyiDxO4&e=
kernel config:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3D7e1bc97341edbea6&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=yeXCTODuJF6ExmCJ-ppqMHsfvMCbCQ9zkmZi3W6NGHo&e=
dashboard link:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3D3610d489778b57cc8031&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=8fAJHh81yojiinnGJzTw6hN4w4A6XRZST4463CWL9Y8&e=
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D15f237aa10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=cPv-hQsGYs0CVz3I26BmauS0hQ8_YTWHeH5p-U5ElWY&e=
C reproducer:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D1553834a10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=r6sGJDOgosZDE9sRxqFnVibDNJFt_6IteSWeqEQLbNE&e=
The bug was bisected to:
commit af6eea57437a830293eab56246b6025cc7d46ee7
Author: Andrii Nakryiko
Date: Mon Mar 30 02:59:58 2020 +
bpf: Implement bpf_link-based cgroup BPF program attachment
bisection log:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_bisect.txt-3Fx-3D1173cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=rJIpYFSAMRfea3349dd7PhmLD_hriVwq8ZtTHcSagBA&e=
final crash:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_report.txt-3Fx-3D1373cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=TWpx5JNdxKiKPABUScn8WB7u3fXueCp7BXwQHg4Unz0&e=
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D1573cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=-SMhn-dVZI4W51EZQ8Im0sdThgwt9M6fxUt3_bcYvk8&e=
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3610d489778b57cc8...@syzkaller.appspotmail.com
Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program
attachment")
general protection fault, probably for non-canonical address
0xdc01: [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0008-0x000f]
CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
01/01/2011
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
No idea why it was bisected to bpf_link change. It seems completely struct
sock-related. Seems like
struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
ends up being NULL.
Can some more networking-savvy people help with investigating this, please?
Well, the repro definitely uses BPF
It does. Even more so, it uses bpf_link_create for cgroup which was
added in my patch. So before it, it just won't be attaching anything. I
just suspect that bug can be repro'ed without cgroup bpf_link and
existed before. This particular repro, though, will always stop on my
commit.
On the following run, my kernel does not have L2TP, so does not crash.
You'd have to use syzbot's kernel config, there is a link to it above.
[pid 817013] bpf(BPF_TASK_FD_QUERY, {task_fd_query={pid=0, fd=-1, flags=0, buf_len=7,
buf="cgroup", prog_id=0, fd_type=BPF_FD_TYPE_RAW_TRACEPOINT, probe_offset=0,
probe_addr=0}}, 48) = -1 ENOENT (No such file or directory)
[pid 817013] openat(AT_FDCWD, "cgroup", O_RDWR|O_PATH) = 3
[pid 817013] bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_CGROUP_SOCK, insn_cnt=4, insns=0x2000,
license="GPL", log_level=0, log_size=0, log_buf=NULL, kern_version=KERNEL_VERSION(0, 0,
0), prog_flags=0, prog_name="", prog_ifindex=0,
expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=-1, func_info_rec_size=8, func_info=NULL,
func_info_cnt=0, line_info_rec_size=16, line_info=NULL, line_info_cnt=0, attach_btf_id=0}, 112) =
-1 EPERM (Operation not permitted)
[pid 817013] bpf(BPF_LINK_CREATE, {link_create={prog_fd=-1, target_fd=3,
attach_type=BPF_CGROUP_I
Re: general protection fault in inet_unhash
On Thu, May 28, 2020 at 11:01 PM 'Andrii Nakryiko' via syzkaller-bugs
wrote:
>
> On 5/28/20 9:44 AM, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit:dc0f3ed1 net: phy: at803x: add cable diagnostics support f..
> > git tree: net-next
> > console output:
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D17289cd210&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=t1v5ZakZM9Aw_9u_I6FbFZ28U0GFs0e9dMMUOyiDxO4&e=
> > kernel config:
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3D7e1bc97341edbea6&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=yeXCTODuJF6ExmCJ-ppqMHsfvMCbCQ9zkmZi3W6NGHo&e=
> > dashboard link:
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3D3610d489778b57cc8031&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=8fAJHh81yojiinnGJzTw6hN4w4A6XRZST4463CWL9Y8&e=
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro:
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D15f237aa10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=cPv-hQsGYs0CVz3I26BmauS0hQ8_YTWHeH5p-U5ElWY&e=
> > C reproducer:
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D1553834a10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=r6sGJDOgosZDE9sRxqFnVibDNJFt_6IteSWeqEQLbNE&e=
> >
> > The bug was bisected to:
> >
> > commit af6eea57437a830293eab56246b6025cc7d46ee7
> > Author: Andrii Nakryiko
> > Date: Mon Mar 30 02:59:58 2020 +
> >
> > bpf: Implement bpf_link-based cgroup BPF program attachment
> >
> > bisection log:
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_bisect.txt-3Fx-3D1173cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=rJIpYFSAMRfea3349dd7PhmLD_hriVwq8ZtTHcSagBA&e=
> > final crash:
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_report.txt-3Fx-3D1373cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=TWpx5JNdxKiKPABUScn8WB7u3fXueCp7BXwQHg4Unz0&e=
> > console output:
> > https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D1573cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=-SMhn-dVZI4W51EZQ8Im0sdThgwt9M6fxUt3_bcYvk8&e=
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+3610d489778b57cc8...@syzkaller.appspotmail.com
> > Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program
> > attachment")
> >
> > general protection fault, probably for non-canonical address
> > 0xdc01: [#1] PREEMPT SMP KASAN
> > KASAN: null-ptr-deref in range [0x0008-0x000f]
> > CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
>
> No idea why it was bisected to bpf_link change. It seems completely
> struct sock-related. Seems like
Hi Andrii,
You can always find a detailed explanation of syzbot bisections under
the "bisection log" link.
> struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
>
> ends up being NULL.
>
> Can some more networking-savvy people help with investigating this, please?
>
> > Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dd 04 00 00 48 8d 7d 08 44 8b
> > 73 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f
> > 85 55 05 00 00 48 8d 7d 14 4c 8b 6d 08 48 b8 00 00
> > RSP: 0018:c90001777d30 EFLAGS: 00010202
> > RAX: dc00 RBX: 88809a6df940 RCX: 8697c242
> > RDX: 0001 RSI: 8697c251 RDI: 0008
> > RBP: R08: 88809f3ae1c0 R09: fbfff1514cc1
> > R10: 8a8a6607 R11: fbfff1514cc0 R12: 88809a6df9b0
> > R13: 0007 R14: R15: 873a4d00
> > FS: 01d2b880() GS:8880ae60() knlGS:
> > CS: 0010 DS: ES: CR0: 80050033
> > CR2: 006cd090 CR3: 9403a000 CR4: 001406f0
> > DR0: DR1: DR2:
> > DR3: DR6: fffe0ff0 DR7: 0400
> > Call Trace:
> > sk_common_release+0xba/0x370 net/core/sock.c:3210
> > inet_create ne
Re: general protection fault in inet_unhash
On 5/28/20 2:01 PM, Andrii Nakryiko wrote:
> On 5/28/20 9:44 AM, syzbot wrote:
>> Hello,
>>
>> syzbot found the following crash on:
>>
>> HEAD commit: dc0f3ed1 net: phy: at803x: add cable diagnostics support f..
>> git tree: net-next
>> console output:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D17289cd210&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=t1v5ZakZM9Aw_9u_I6FbFZ28U0GFs0e9dMMUOyiDxO4&e=
>> kernel config:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3D7e1bc97341edbea6&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=yeXCTODuJF6ExmCJ-ppqMHsfvMCbCQ9zkmZi3W6NGHo&e=
>> dashboard link:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3D3610d489778b57cc8031&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=8fAJHh81yojiinnGJzTw6hN4w4A6XRZST4463CWL9Y8&e=
>> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>> syz repro:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D15f237aa10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=cPv-hQsGYs0CVz3I26BmauS0hQ8_YTWHeH5p-U5ElWY&e=
>> C reproducer:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D1553834a10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=r6sGJDOgosZDE9sRxqFnVibDNJFt_6IteSWeqEQLbNE&e=
>>
>> The bug was bisected to:
>>
>> commit af6eea57437a830293eab56246b6025cc7d46ee7
>> Author: Andrii Nakryiko
>> Date: Mon Mar 30 02:59:58 2020 +
>>
>> bpf: Implement bpf_link-based cgroup BPF program attachment
>>
>> bisection log:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_bisect.txt-3Fx-3D1173cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=rJIpYFSAMRfea3349dd7PhmLD_hriVwq8ZtTHcSagBA&e=
>> final crash:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_report.txt-3Fx-3D1373cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=TWpx5JNdxKiKPABUScn8WB7u3fXueCp7BXwQHg4Unz0&e=
>> console output:
>> https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D1573cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=-SMhn-dVZI4W51EZQ8Im0sdThgwt9M6fxUt3_bcYvk8&e=
>>
>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>> Reported-by: syzbot+3610d489778b57cc8...@syzkaller.appspotmail.com
>> Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program
>> attachment")
>>
>> general protection fault, probably for non-canonical address
>> 0xdc01: [#1] PREEMPT SMP KASAN
>> KASAN: null-ptr-deref in range [0x0008-0x000f]
>> CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
>> Google 01/01/2011
>> RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
>
> No idea why it was bisected to bpf_link change. It seems completely struct
> sock-related. Seems like
>
> struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
>
> ends up being NULL.
>
> Can some more networking-savvy people help with investigating this, please?
Well, the repro definitely uses BPF
On the following run, my kernel does not have L2TP, so does not crash.
[pid 817013] bpf(BPF_TASK_FD_QUERY, {task_fd_query={pid=0, fd=-1, flags=0,
buf_len=7, buf="cgroup", prog_id=0, fd_type=BPF_FD_TYPE_RAW_TRACEPOINT,
probe_offset=0, probe_addr=0}}, 48) = -1 ENOENT (No such file or directory)
[pid 817013] openat(AT_FDCWD, "cgroup", O_RDWR|O_PATH) = 3
[pid 817013] bpf(BPF_PROG_LOAD, {prog_type=BPF_PROG_TYPE_CGROUP_SOCK,
insn_cnt=4, insns=0x2000, license="GPL", log_level=0, log_size=0,
log_buf=NULL, kern_version=KERNEL_VERSION(0, 0, 0), prog_flags=0, prog_name="",
prog_ifindex=0, expected_attach_type=BPF_CGROUP_INET_INGRESS, prog_btf_fd=-1,
func_info_rec_size=8, func_info=NULL, func_info_cnt=0, line_info_rec_size=16,
line_info=NULL, line_info_cnt=0, attach_btf_id=0}, 112) = -1 EPERM (Operation
not permitted)
[pid 817013] bpf(BPF_LINK_CREATE, {link_create={prog_fd=-1, target_fd=3,
attach_type=BPF_CGROUP_INET_SOCK_CREATE, flags=0}}, 16) = -1 EBADF (Bad file
descriptor)
[pid 817013] socket(AF_INET, SOCK_DGRAM, IPPROTO_L2TP
[pid 816180] <... nanosleep resumed>NULL) = 0
[pid 816180] wait4(-1, 0x7fffa59867cc, WNOHANG|__WALL, NULL) = 0
[pid 816180] nanosleep({tv_sec=0,
Re: general protection fault in inet_unhash
On 5/28/20 9:44 AM, syzbot wrote:
Hello,
syzbot found the following crash on:
HEAD commit:dc0f3ed1 net: phy: at803x: add cable diagnostics support f..
git tree: net-next
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D17289cd210&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=t1v5ZakZM9Aw_9u_I6FbFZ28U0GFs0e9dMMUOyiDxO4&e=
kernel config:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_.config-3Fx-3D7e1bc97341edbea6&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=yeXCTODuJF6ExmCJ-ppqMHsfvMCbCQ9zkmZi3W6NGHo&e=
dashboard link:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_bug-3Fextid-3D3610d489778b57cc8031&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=8fAJHh81yojiinnGJzTw6hN4w4A6XRZST4463CWL9Y8&e=
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.syz-3Fx-3D15f237aa10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=cPv-hQsGYs0CVz3I26BmauS0hQ8_YTWHeH5p-U5ElWY&e=
C reproducer:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_repro.c-3Fx-3D1553834a10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=r6sGJDOgosZDE9sRxqFnVibDNJFt_6IteSWeqEQLbNE&e=
The bug was bisected to:
commit af6eea57437a830293eab56246b6025cc7d46ee7
Author: Andrii Nakryiko
Date: Mon Mar 30 02:59:58 2020 +
bpf: Implement bpf_link-based cgroup BPF program attachment
bisection log:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_bisect.txt-3Fx-3D1173cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=rJIpYFSAMRfea3349dd7PhmLD_hriVwq8ZtTHcSagBA&e=
final crash:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_report.txt-3Fx-3D1373cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=TWpx5JNdxKiKPABUScn8WB7u3fXueCp7BXwQHg4Unz0&e=
console output:
https://urldefense.proofpoint.com/v2/url?u=https-3A__syzkaller.appspot.com_x_log.txt-3Fx-3D1573cd7e10&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=-SMhn-dVZI4W51EZQ8Im0sdThgwt9M6fxUt3_bcYvk8&e=
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3610d489778b57cc8...@syzkaller.appspotmail.com
Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program
attachment")
general protection fault, probably for non-canonical address
0xdc01: [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0008-0x000f]
CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
01/01/2011
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
No idea why it was bisected to bpf_link change. It seems completely
struct sock-related. Seems like
struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
ends up being NULL.
Can some more networking-savvy people help with investigating this, please?
Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dd 04 00 00 48 8d 7d 08 44 8b 73 08 48
b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 55 05 00 00
48 8d 7d 14 4c 8b 6d 08 48 b8 00 00
RSP: 0018:c90001777d30 EFLAGS: 00010202
RAX: dc00 RBX: 88809a6df940 RCX: 8697c242
RDX: 0001 RSI: 8697c251 RDI: 0008
RBP: R08: 88809f3ae1c0 R09: fbfff1514cc1
R10: 8a8a6607 R11: fbfff1514cc0 R12: 88809a6df9b0
R13: 0007 R14: R15: 873a4d00
FS: 01d2b880() GS:8880ae60() knlGS:
CS: 0010 DS: ES: CR0: 80050033
CR2: 006cd090 CR3: 9403a000 CR4: 001406f0
DR0: DR1: DR2:
DR3: DR6: fffe0ff0 DR7: 0400
Call Trace:
sk_common_release+0xba/0x370 net/core/sock.c:3210
inet_create net/ipv4/af_inet.c:390 [inline]
inet_create+0x966/0xe00 net/ipv4/af_inet.c:248
__sock_create+0x3cb/0x730 net/socket.c:1428
sock_create net/socket.c:1479 [inline]
__sys_socket+0xef/0x200 net/socket.c:1521
__do_sys_socket net/socket.c:1530 [inline]
__se_sys_socket net/socket.c:1528 [inline]
__x64_sys_socket+0x6f/0xb0 net/socket.c:1528
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49
general protection fault in inet_unhash
Hello,
syzbot found the following crash on:
HEAD commit:dc0f3ed1 net: phy: at803x: add cable diagnostics support f..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17289cd210
kernel config: https://syzkaller.appspot.com/x/.config?x=7e1bc97341edbea6
dashboard link: https://syzkaller.appspot.com/bug?extid=3610d489778b57cc8031
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15f237aa10
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1553834a10
The bug was bisected to:
commit af6eea57437a830293eab56246b6025cc7d46ee7
Author: Andrii Nakryiko
Date: Mon Mar 30 02:59:58 2020 +
bpf: Implement bpf_link-based cgroup BPF program attachment
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1173cd7e10
final crash:https://syzkaller.appspot.com/x/report.txt?x=1373cd7e10
console output: https://syzkaller.appspot.com/x/log.txt?x=1573cd7e10
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+3610d489778b57cc8...@syzkaller.appspotmail.com
Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program
attachment")
general protection fault, probably for non-canonical address
0xdc01: [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0008-0x000f]
CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
01/01/2011
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dd 04 00 00 48 8d 7d 08 44 8b 73
08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 55 05
00 00 48 8d 7d 14 4c 8b 6d 08 48 b8 00 00
RSP: 0018:c90001777d30 EFLAGS: 00010202
RAX: dc00 RBX: 88809a6df940 RCX: 8697c242
RDX: 0001 RSI: 8697c251 RDI: 0008
RBP: R08: 88809f3ae1c0 R09: fbfff1514cc1
R10: 8a8a6607 R11: fbfff1514cc0 R12: 88809a6df9b0
R13: 0007 R14: R15: 873a4d00
FS: 01d2b880() GS:8880ae60() knlGS:
CS: 0010 DS: ES: CR0: 80050033
CR2: 006cd090 CR3: 9403a000 CR4: 001406f0
DR0: DR1: DR2:
DR3: DR6: fffe0ff0 DR7: 0400
Call Trace:
sk_common_release+0xba/0x370 net/core/sock.c:3210
inet_create net/ipv4/af_inet.c:390 [inline]
inet_create+0x966/0xe00 net/ipv4/af_inet.c:248
__sock_create+0x3cb/0x730 net/socket.c:1428
sock_create net/socket.c:1479 [inline]
__sys_socket+0xef/0x200 net/socket.c:1521
__do_sys_socket net/socket.c:1530 [inline]
__se_sys_socket net/socket.c:1528 [inline]
__x64_sys_socket+0x6f/0xb0 net/socket.c:1528
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x441e29
Code: e8 fc b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:7ffdce184148 EFLAGS: 0246 ORIG_RAX: 0029
RAX: ffda RBX: 0003 RCX: 00441e29
RDX: 0073 RSI: 0002 RDI: 0002
RBP: R08: R09:
R10: R11: 0246 R12:
R13: 00402c30 R14: R15:
Modules linked in:
---[ end trace 23b6578228ce553e ]---
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dd 04 00 00 48 8d 7d 08 44 8b 73
08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 55 05
00 00 48 8d 7d 14 4c 8b 6d 08 48 b8 00 00
RSP: 0018:c90001777d30 EFLAGS: 00010202
RAX: dc00 RBX: 88809a6df940 RCX: 8697c242
RDX: 0001 RSI: 8697c251 RDI: 0008
RBP: R08: 88809f3ae1c0 R09: fbfff1514cc1
R10: 8a8a6607 R11: fbfff1514cc0 R12: 88809a6df9b0
R13: 0007 R14: R15: 873a4d00
FS: 01d2b880() GS:8880ae60() knlGS:
CS: 0010 DS: ES: CR0: 80050033
CR2: 006cd090 CR3: 9403a000 CR4: 001406f0
DR0: DR1: DR2:
DR3: DR6: fffe0ff0 DR7: 0400
---
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 syzkal...@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with sy
