general protection fault in sctp_backlog_rcv

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 80bd9028feca Add linux-next specific files for 20230131
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1738c41d480000
kernel config: https://syzkaller.appspot.com/x/.config?x=904dc2f450eaad4a
dashboard link: https://syzkaller.appspot.com/bug?extid=174db8e2963d950bb50d
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
CC: [da...@davemloft.net edum...@google.com ku...@kernel.org linux-...@vger.kernel.org linux...@vger.kernel.org marcelo...@gmail.com net...@vger.kernel.org nho...@tuxdriver.com pab...@redhat.com vyas...@gmail.com]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/924618188238/disk-80bd9028.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7a03cf86e545/vmlinux-80bd9028.xz
kernel image: https://storage.googleapis.com/syzbot-assets/568e80043a41/bzImage-80bd9028.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+174db8...@syzkaller.appspotmail.com

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: 5574 Comm: syz-executor.4 Not tainted 6.2.0-rc6-next-20230131-syzkaller-09515-g80bd9028feca #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
RIP: 0010:sctp_backlog_rcv+0xaf/0x5b0 net/sctp/input.c:290
Code: 48 8d 5d 20 0f 85 b1 04 00 00 49 8b 85 e8 00 00 00 48 8d 7d 08 48 89 fa 48 c1 ea 03 48 89 04 24 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 02 84 c0 74 06 0f 8e 0c 03 00 00 44 0f b6 7d 08 31 ff 44
RSP: 0018:ffffc90005b1fc00 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000020 RCX: ffffc900044e5000
RDX: 0000000000000001 RSI: ffffffff89605e0d RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000094001 R12: ffff88814a802d00
R13: ffff8880778f2140 R14: ffff888070bb3c80 R15: 0000000000000000
FS: 00007f0eda6af700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555555c2888 CR3: 0000000029fe1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
sk_backlog_rcv include/net/sock.h:1113 [inline]
__release_sock+0x133/0x3b0 net/core/sock.c:2928
release_sock+0x58/0x1b0 net/core/sock.c:3487
sctp_setsockopt+0x64a/0xab90 net/sctp/socket.c:4772
__sys_setsockopt+0x2c6/0x5b0 net/socket.c:2271
__do_sys_setsockopt net/socket.c:2282 [inline]
__se_sys_setsockopt net/socket.c:2279 [inline]
__x64_sys_setsockopt+0xbe/0x160 net/socket.c:2279
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f0ed988c0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0eda6af168 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f0ed99ac050 RCX: 00007f0ed988c0c9
RDX: 0000000000000009 RSI: 0000000000000084 RDI: 0000000000000004
RBP: 00007f0ed98e7ae9 R08: 000000000000009c R09: 0000000000000000
R10: 0000000020000500 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc6d02065f R14: 00007f0eda6af300 R15: 0000000000022000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:sctp_backlog_rcv+0xaf/0x5b0 net/sctp/input.c:290
Code: 48 8d 5d 20 0f 85 b1 04 00 00 49 8b 85 e8 00 00 00 48 8d 7d 08 48 89 fa 48 c1 ea 03 48 89 04 24 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 02 84 c0 74 06 0f 8e 0c 03 00 00 44 0f b6 7d 08 31 ff 44
RSP: 0018:ffffc90005b1fc00 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000020 RCX: ffffc900044e5000
RDX: 0000000000000001 RSI: ffffffff89605e0d RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000094001 R12: ffff88814a802d00
R13: ffff8880778f2140 R14: ffff888070bb3c80 R15: 0000000000000000
FS: 00007f0eda6af700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f53601ad988 CR3: 0000000029fe1000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 48 8d 5d 20 lea 0x20(%rbp),%rbx
4: 0f 85 b1 04 00 00 jne 0x4bb
a: 49 8b 85 e8 00 00 00 mov 0xe8(%r13),%rax
11: 48 8d 7d 08 lea 0x8(%rbp),%rdi
15: 48 89 fa mov %rdi,%rdx
18: 48 c1 ea 03 shr $0x3,%rdx
1c: 48 89 04 24 mov %rax,(%rsp)
20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
27: fc ff df
* 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction
2e: 84 c0 test %al,%al
30: 74 06 je 0x38
32: 0f 8e 0c 03 00 00 jle 0x344
38: 44 0f b6 7d 08 movzbl 0x8(%rbp),%r15d
3d: 31 ff xor %edi,%edi
3f: 44 rex.R


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.