From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f71.google.com (mail-oo1-f71.google.com [209.85.161.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 134E22BE02A for ; Mon, 16 Feb 2026 02:35:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771209325; cv=none; b=dp6MjrKNqNzCuk9aQHmAyuPWLIBFvVshL45PRdWZs1QgGFuDaqX5BLCj4Dx9MVUtxFwp8d/VK/x6/zvFkW6jb6faGDByoLTZvz9gk5p3td+le2dFIHWrcRK2EpPd/G+KVGbIPD93yrzGPk328kwxQmeXBYRgY9ORsZgQ4n7naa4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771209325; c=relaxed/simple; bh=GQEa7gJOW5rm5wKgZzMmOJ1EY4oQtylppNdd5D0uh0M=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; 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006d021491bc7-678afd1a48emr2596730eaf.69.1771209322111; Sun, 15 Feb 2026 18:35:22 -0800 (PST) Date: Sun, 15 Feb 2026 18:35:22 -0800 In-Reply-To: <68c95a83.050a0220.3c6139.0e5c.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6992826a.050a0220.340abe.0587.GAE@google.com> Subject: Re: [syzbot] [net?] general protection fault in lec_arp_clear_vccs From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 37a93dd5c49b Merge tag 'net-next-7.0' of git://git.kernel... git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=17972ffa580000 kernel config: https://syzkaller.appspot.com/x/.config?x=17f5c46dd78c01cf dashboard link: https://syzkaller.appspot.com/bug?extid=72e3ea390c305de0e259 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1756015a580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=145a2722580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/05288cb3a544/disk-37a93dd5.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8b208672ebc8/vmlinux-37a93dd5.xz kernel image: https://storage.googleapis.com/syzbot-assets/cb0ca59bc74a/bzImage-37a93dd5.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+72e3ea390c305de0e259@syzkaller.appspotmail.com Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 UID: 0 PID: 8024 Comm: syz.3.396 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:lec_arp_clear_vccs+0xad/0x380 net/atm/lec.c:1263 Code: e8 03 80 3c 28 00 74 08 4c 89 e7 e8 5d f6 62 f7 4c 89 74 24 18 49 8b 2c 24 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 35 f6 62 f7 4d 8b 75 00 4d 8d a7 30 RSP: 0018:ffffc9000cc67bc8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88807efa2400 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8c2764e0 RDI: ffff88807efa2400 RBP: ffff888057c3c000 R08: ffffffff8ef0f2f3 R09: 1ffffffff1de1e5e R10: dffffc0000000000 R11: fffffbfff1de1e5f R12: ffff88803352e650 R13: 0000000000000000 R14: ffff88807efa2430 R15: ffff88803352e000 FS: 0000555590f50500(0000) GS:ffff8881254b0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffef315f148 CR3: 00000000722fa000 CR4: 00000000003526f0 Call Trace: lec_vcc_close net/atm/lec.c:2183 [inline] lec_push+0x3cb/0x19d0 net/atm/lec.c:594 vcc_destroy_socket net/atm/common.c:183 [inline] vcc_release+0x15f/0x580 net/atm/common.c:205 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f005119bf79 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff437a3bc8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f0051417da0 RCX: 00007f005119bf79 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f0051417da0 R08: 00007f0051416128 R09: 0000000000000000 R10: 000000000003fd6c R11: 0000000000000246 R12: 000000000002c374 R13: 00007f0051415fac R14: 000000000002c122 R15: 00007fff437a3cd0 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:lec_arp_clear_vccs+0xad/0x380 net/atm/lec.c:1263 Code: e8 03 80 3c 28 00 74 08 4c 89 e7 e8 5d f6 62 f7 4c 89 74 24 18 49 8b 2c 24 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 35 f6 62 f7 4d 8b 75 00 4d 8d a7 30 RSP: 0018:ffffc9000cc67bc8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88807efa2400 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8c2764e0 RDI: ffff88807efa2400 RBP: ffff888057c3c000 R08: ffffffff8ef0f2f3 R09: 1ffffffff1de1e5e R10: dffffc0000000000 R11: fffffbfff1de1e5f R12: ffff88803352e650 R13: 0000000000000000 R14: ffff88807efa2430 R15: ffff88803352e000 FS: 0000555590f50500(0000) GS:ffff8881254b0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffef315f148 CR3: 00000000722fa000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: e8 03 80 3c 28 call 0x283c8008 5: 00 74 08 4c add %dh,0x4c(%rax,%rcx,1) 9: 89 e7 mov %esp,%edi b: e8 5d f6 62 f7 call 0xf762f66d 10: 4c 89 74 24 18 mov %r14,0x18(%rsp) 15: 49 8b 2c 24 mov (%r12),%rbp 19: 4c 89 e8 mov %r13,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 4c 89 ef mov %r13,%rdi 33: e8 35 f6 62 f7 call 0xf762f66d 38: 4d 8b 75 00 mov 0x0(%r13),%r14 3c: 4d rex.WRB 3d: 8d .byte 0x8d 3e: a7 cmpsl %es:(%rdi),%ds:(%rsi) 3f: 30 .byte 0x30 --- 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.