On Fri, May 29, 2020 at 8:33 AM Andrii Nakryiko <andr...@fb.com> 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 > > <syzkaller-b...@googlegroups.com> 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-3D17289cd2100000&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-3D15f237aa100000&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-3D1553834a100000&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=r6sGJDOgosZDE9sRxqFnVibDNJFt_6IteSWeqEQLbNE&e= > >>> > >>> The bug was bisected to: > >>> > >>> commit af6eea57437a830293eab56246b6025cc7d46ee7 > >>> Author: Andrii Nakryiko <andr...@fb.com> > >>> Date: Mon Mar 30 02:59:58 2020 +0000 > >>> > >>> 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-3D1173cd7e100000&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-3D1373cd7e100000&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-3D1573cd7e100000&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 > >>> 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN > >>> KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] > >>> 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 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:ffffc90001777d30 EFLAGS: 00010202 > >>> RAX: dffffc0000000000 RBX: ffff88809a6df940 RCX: ffffffff8697c242 > >>> RDX: 0000000000000001 RSI: ffffffff8697c251 RDI: 0000000000000008 > >>> RBP: 0000000000000000 R08: ffff88809f3ae1c0 R09: fffffbfff1514cc1 > >>> R10: ffffffff8a8a6607 R11: fffffbfff1514cc0 R12: ffff88809a6df9b0 > >>> R13: 0000000000000007 R14: 0000000000000000 R15: ffffffff873a4d00 > >>> FS: 0000000001d2b880(0000) GS:ffff8880ae600000(0000) > >>> knlGS:0000000000000000 > >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >>> CR2: 00000000006cd090 CR3: 000000009403a000 CR4: 00000000001406f0 > >>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > >>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > >>> 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:00007ffdce184148 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 > >>> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441e29 > >>> RDX: 0000000000000073 RSI: 0000000000000002 RDI: 0000000000000002 > >>> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > >>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > >>> R13: 0000000000402c30 R14: 0000000000000000 R15: 0000000000000000 > >>> 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:ffffc90001777d30 EFLAGS: 00010202 > >>> RAX: dffffc0000000000 RBX: ffff88809a6df940 RCX: ffffffff8697c242 > >>> RDX: 0000000000000001 RSI: ffffffff8697c251 RDI: 0000000000000008 > >>> RBP: 0000000000000000 R08: ffff88809f3ae1c0 R09: fffffbfff1514cc1 > >>> R10: ffffffff8a8a6607 R11: fffffbfff1514cc0 R12: ffff88809a6df9b0 > >>> R13: 0000000000000007 R14: 0000000000000000 R15: ffffffff873a4d00 > >>> FS: 0000000001d2b880(0000) GS:ffff8880ae600000(0000) > >>> knlGS:0000000000000000 > >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >>> CR2: 00000000006cd090 CR3: 000000009403a000 CR4: 00000000001406f0 > >>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > >>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > >>> > >>> > >>> --- > >>> This bug is generated by a bot. It may contain errors. > >>> See > >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__goo.gl_tpsmEJ&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=NELwknC4AyuWSJIHbwt_O_c0jfPc_6D9RuKHh_adQ_Y&e= > >>> for more information about syzbot. > >>> syzbot engineers can be reached at syzkal...@googlegroups.com. > >>> > >>> syzbot will keep track of this bug report. See: > >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__goo.gl_tpsmEJ-23status&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=YfV-e6A04EIqHwezxYop7CpJyhXD8DVzwTPUT0xckaM&e= > >>> for how to communicate with syzbot. > >>> For information about bisection process see: > >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__goo.gl_tpsmEJ-23bisection&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=xOFzqI48uvECf4XFjlhNl4LBOT02lz1HlCL6MT1uMrI&e= > >>> syzbot can test patches for this bug, for details see: > >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__goo.gl_tpsmEJ-23testing-2Dpatches&d=DwIBaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=sMAtpavBBjBzFzT0V8c6FcH8cu2M9da3ZozO5Lc8do0&s=_cj6MOAz3yNlXgjMuyRu6ZOEjRvYWEvtTd7kE46wVfo&e= > >>> > >> > >> -- > >> You received this message because you are subscribed to the Google Groups > >> "syzkaller-bugs" group. > >> To unsubscribe from this group and stop receiving emails from it, send an > >> email to syzkaller-bugs+unsubscr...@googlegroups.com. > >> To view this discussion on the web visit > >> https://urldefense.proofpoint.com/v2/url?u=https-3A__groups.google.com_d_msgid_syzkaller-2Dbugs_d65c8424-2De78c-2D63f9-2D3711-2D532494619dc6-2540fb.com&d=DwIFaQ&c=5VD0RTtNlTh3ycd41b3MUw&r=vxqvl81C2rT6GOGdPyz8iQ&m=b2VQiGg0nrxk96tqrmflMQ24DJk-MOxx4uyOs7wSUJ0&s=TYFus0Dh0-ZHiL510kJIyPOWCyX34UzLWR4QvS3r_iY&e= > >> . >