Re: [syzbot] [net?] WARNING in inet_sock_destruct (4)

[Muhammad Usama Anjum <usama.anjum@collabora.com>]

On 6/23/23 7:36 PM, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit: 45a3e24f65e9 Linux 6.4-rc7
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=160cc82f280000
> kernel config: https://syzkaller.appspot.com/x/.config?x=2cbd298d0aff1140
> dashboard link: https://syzkaller.appspot.com/bug?extid=de6565462ab540f50e47
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=160aacb7280000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17c115d3280000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/c09bcd4ec365/disk-45a3e24f.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/03549b639718/vmlinux-45a3e24f.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/91f203e5f63e/bzImage-45a3e24f.xz
> 
> The issue was bisected to:
> 
> commit 565b4824c39fa335cba2028a09d7beb7112f3c9a
> Author: Jiri Pirko <jiri@nvidia.com>
> Date: Mon Feb 6 09:41:51 2023 +0000
> 
> devlink: change port event netdev notifier from per-net to global
> 
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=110a1a5b280000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=130a1a5b280000
> console output: https://syzkaller.appspot.com/x/log.txt?x=150a1a5b280000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+de6565462ab540f50e47@syzkaller.appspotmail.com
> Fixes: 565b4824c39f ("devlink: change port event netdev notifier from per-net to global")
> 
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 5025 at net/ipv4/af_inet.c:154 inet_sock_destruct+0x6df/0x8a0 net/ipv4/af_inet.c:154
This same warning has been spotted and reported:
https://bugzilla.kernel.org/show_bug.cgi?id=217555

Syzbot has found the same warning on 4.14, 5.15, 6.1, 6.5-rc and latest
mainline (1c59d383390f9) kernels. The provided reproducers (such as
https://syzkaller.appspot.com/text?tag=ReproC&x=15a10e8aa80000) are
reproducing the same warnings on multicore (at least 2 CPUs) qemu instance.

> Modules linked in:
> CPU: 0 PID: 5025 Comm: syz-executor250 Not tainted 6.4.0-rc7-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
> RIP: 0010:inet_sock_destruct+0x6df/0x8a0 net/ipv4/af_inet.c:154
> Code: ff e8 c5 9f e0 f8 0f 0b e9 07 fe ff ff e8 b9 9f e0 f8 0f 0b e9 3f fe ff ff e8 ad 9f e0 f8 0f 0b e9 95 fd ff ff e8 a1 9f e0 f8 <0f> 0b e9 9f fe ff ff e8 d5 6a 33 f9 e9 7a fc ff ff 4c 89 e7 e8 08
> RSP: 0018:ffffc90000007de8 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: 00000000fffff000 RCX: 0000000000000100
> RDX: ffff8880792f8000 RSI: ffffffff88a3a73f RDI: 0000000000000005
> RBP: ffff88814aa99980 R08: 0000000000000005 R09: 0000000000000000
> R10: 00000000fffff000 R11: 0000000000094001 R12: ffff88814aa999a8
> R13: ffff88814aa99bf4 R14: ffffc90000007ed8 R15: 0000000000000004
> FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f579b4f6ec8 CR3: 000000000c571000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <IRQ>
> __sk_destruct+0x4d/0x770 net/core/sock.c:2130
> rcu_do_batch kernel/rcu/tree.c:2115 [inline]
> rcu_core+0x806/0x1ad0 kernel/rcu/tree.c:2377
> __do_softirq+0x1d4/0x905 kernel/softirq.c:571
> invoke_softirq kernel/softirq.c:445 [inline]
> __irq_exit_rcu+0x114/0x190 kernel/softirq.c:650
> irq_exit_rcu+0x9/0x20 kernel/softirq.c:662
> sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1106
> </IRQ>
> <TASK>
> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
> RIP: 0010:write_comp_data+0x3c/0x90 kernel/kcov.c:236
> Code: 01 00 00 49 89 f8 65 48 8b 14 25 c0 bb 03 00 a9 00 01 ff 00 74 0e 85 f6 74 59 8b 82 0c 16 00 00 85 c0 74 4f 8b 82 e8 15 00 00 <83> f8 03 75 44 48 8b 82 f0 15 00 00 8b 92 ec 15 00 00 48 8b 38 48
> RSP: 0018:ffffc90003a7fbf8 EFLAGS: 00000246
> RAX: 0000000000000000 RBX: ffffc90003a7b020 RCX: ffffffff814d76d1
> RDX: ffff8880792f8000 RSI: 0000000000000000 RDI: 0000000000000007
> RBP: ffff8880792f8000 R08: 0000000000000007 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000094001 R12: 0000000000000000
> R13: ffffc90003a78000 R14: dffffc0000000000 R15: ffff8880792f85f8
> stack_not_used include/linux/sched/task_stack.h:107 [inline]
> check_stack_usage kernel/exit.c:776 [inline]
> do_exit+0x17f1/0x29b0 kernel/exit.c:918
> do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
> get_signal+0x2318/0x25b0 kernel/signal.c:2876
> arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
> exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
> exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
> __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
> syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
> do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
> entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f579b4a1d39
> Code: Unable to access opcode bytes at 0x7f579b4a1d0f.
> RSP: 002b:00007f579b431308 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
> RAX: fffffffffffffe00 RBX: 00007f579b52a4d8 RCX: 00007f579b4a1d39
> RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f579b52a4d8
> RBP: 00007f579b52a4d0 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f579b4f72c0
> R13: 00007f579b52a4dc R14: 00007f579b431400 R15: 0000000000022000
> </TASK>
> ----------------
> Code disassembly (best guess):
> 0: 01 00 add %eax,(%rax)
> 2: 00 49 89 add %cl,-0x77(%rcx)
> 5: f8 clc
> 6: 65 48 8b 14 25 c0 bb mov %gs:0x3bbc0,%rdx
> d: 03 00
> f: a9 00 01 ff 00 test $0xff0100,%eax
> 14: 74 0e je 0x24
> 16: 85 f6 test %esi,%esi
> 18: 74 59 je 0x73
> 1a: 8b 82 0c 16 00 00 mov 0x160c(%rdx),%eax
> 20: 85 c0 test %eax,%eax
> 22: 74 4f je 0x73
> 24: 8b 82 e8 15 00 00 mov 0x15e8(%rdx),%eax
> * 2a: 83 f8 03 cmp $0x3,%eax <-- trapping instruction
> 2d: 75 44 jne 0x73
> 2f: 48 8b 82 f0 15 00 00 mov 0x15f0(%rdx),%rax
> 36: 8b 92 ec 15 00 00 mov 0x15ec(%rdx),%edx
> 3c: 48 8b 38 mov (%rax),%rdi
> 3f: 48 rex.W
> 
> 
> ---
> This report 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 syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
> 
> If the bug is already fixed, let syzbot know by replying with:
> #syz fix: exact-commit-title
> 
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
> 
> If you want to change bug's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
> 
> If the bug is a duplicate of another bug, reply with:
> #syz dup: exact-subject-of-another-report
> 
> If you want to undo deduplication, reply with:
> #syz undup
> 

-- 
BR,
Muhammad Usama Anjum