From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f199.google.com (mail-il1-f199.google.com [209.85.166.199]) (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 BCD2C2248AE for ; Wed, 26 Nov 2025 08:16:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764144975; cv=none; b=LjLdwQP7xP3/BEXip718YaEBP+7ACCUD6R1IgJcr0tyqRF13DGkMDNaNvogVqtvWVIq8IkyKxA6Ql/N7J7iUUPc67I0wfZjeYpY/D4OiFgeBbWSKt1OqTaOgZM9x8yx4M6cQa/BeTdMBhkRXejUvNhxJyjmchTk+XGb84z41Ye8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764144975; c=relaxed/simple; bh=paGpx1Oa8J+Ki16wybCrw0vFUSnFc3+ZWphHQ1j872g=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To:Cc: Content-Type; b=aG9vEsf2i8uCDMmAbJNKFZy1bs8UnwCq48RCmPVyy8nqvPBRwbYGjtXWoSyJxnnMVBcLbqRAld3Z1mjudQfeihJblU69OvazcIjsmmI3+tfB3aH8HEwiBhke3rLBk1cjwtdguIZWpWWBQGYSrdN67AHvRECiVX497Vi8q39XNU4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-il1-f199.google.com with SMTP id e9e14a558f8ab-4347bc50df4so6462335ab.0 for ; Wed, 26 Nov 2025 00:16:13 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764144973; x=1764749773; h=cc:to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=GV7L64Lukxwhs4+pNd9OeGnnt4P82bXGOhYOkGbjhyc=; b=NNv1tCts+LUTkO4ja2IzAu7ck4vrhbCXYsJLQL2tF15rRJPlUkQZFkKqvIiuQLBE0W Ef1dpajxD3AT/+GJoF8MuHC5LWKmC+uabwy9H9z/DkZgI/TYzq40FI85g0KAL4v4HkoT UupC3uyb7KvbfTDlJPF0D+bKO7Fmdt0H7rNFEHCqRFXgMp4ObFWekqqFcVEP4Xy2BKNi J5FergGc0IGh4yauKKyHXH3lld0DZfMxw0s7xj6lcUst5C0Q5Nft2VTaTZuFe5ex5Cnz pXmvqmpq+zTRi2SCE/AF1I6YsbRW9SEMSCZCuGjbQmW3sxdU0EB+mWS2kZD5MkLQw2Ua K7yw== X-Forwarded-Encrypted: i=1; AJvYcCWVZpnXKWm8/ch/9Fz9H3r4nqjgLJ32okQm+Q1wp24Xt9+8kXS4dBt4pDKqh86T+0qyf7DLD3o=@vger.kernel.org X-Gm-Message-State: AOJu0Yz4Tgoqby1s0YIXLt0MrAtN7AP2xDbrHTG4ivdDcBKS/tfs72B6 jIAHWNysQy9yQzsGZSsGgz2kh0BxouSq/40ANY/bAhSrg79oTbMm90OBPIK0VIPdRqUiK6fExOq osLBLzENWZeH7UAbnlfi07Odpz4uFe6avgSWfVCpacbiB0bOWzHfHpaM8GZI= X-Google-Smtp-Source: AGHT+IHhzXzUmxFpN2a7S+4xTfO5tz6udl/gx+iHQbfZ9mbRbJv32etnuETAGyXGLw8MpES/tuu9m7rvRiTzifzrpnqrP4+vG2VF Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:198b:b0:435:a410:d8b5 with SMTP id e9e14a558f8ab-435b9030219mr196964365ab.1.1764144972903; Wed, 26 Nov 2025 00:16:12 -0800 (PST) Date: Wed, 26 Nov 2025 00:16:12 -0800 In-Reply-To: <20251125224604.872351-1-victor@mojatatu.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6926b74c.a70a0220.d98e3.00cf.GAE@google.com> Subject: [syzbot ci] Re: net/sched: Introduce qdisc quirk_chk op From: syzbot ci To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, jhs@mojatatu.com, jiri@resnulli.us, kuba@kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, stephen@networkplumber.org, victor@mojatatu.com, xiyou.wangcong@gmail.com Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v2] net/sched: Introduce qdisc quirk_chk op https://lore.kernel.org/all/20251125224604.872351-1-victor@mojatatu.com * [RFC PATCH net-next v2] net/sched: Introduce qdisc quirk_chk op and found the following issue: general protection fault in netem_quirk_chk Full report is available here: https://ci.syzbot.org/series/aa7207e5-00c6-4c9d-b330-9b2041104daf *** general protection fault in netem_quirk_chk tree: net-next URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net-next.git base: e2c20036a8879476c88002730d8a27f4e3c32d4b arch: amd64 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 config: https://ci.syzbot.org/builds/bbda2e20-2099-41bd-a7d4-c298c61ed2f5/config C repro: https://ci.syzbot.org/findings/21f8d5f6-c5af-4e81-a8d5-56f5febd6f03/c_repro syz repro: https://ci.syzbot.org/findings/21f8d5f6-c5af-4e81-a8d5-56f5febd6f03/syz_repro netlink: 28 bytes leftover after parsing attributes in process `syz.0.17'. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 UID: 0 PID: 5961 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 RIP: 0010:nla_len include/net/netlink.h:1296 [inline] RIP: 0010:parse_attr net/sched/sch_netem.c:960 [inline] RIP: 0010:netem_quirk_chk+0x8a/0x740 net/sched/sch_netem.c:990 Code: 7c 24 60 49 c1 ef 03 43 c7 04 27 f1 f1 f1 f1 43 c7 44 27 13 f3 f3 f3 f3 43 c6 44 27 17 f3 e8 8d 68 67 f8 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 32 06 00 00 0f b7 03 83 c0 fc 44 0f b7 RSP: 0018:ffffc900032c7140 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88810ff73a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881b82ce000 RBP: ffffc900032c72b8 R08: ffff88810ff73a00 R09: 0000000000000002 R10: 00000000fffffff1 R11: ffffffff89589ab0 R12: dffffc0000000000 R13: ffffffff89589ab0 R14: ffffffff8f7d9580 R15: 1ffff92000658e34 FS: 000055558efa7500(0000) GS:ffff8882a9f35000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000100 CR3: 0000000114760000 CR4: 00000000000006f0 Call Trace: qdisc_create+0x73f/0xf10 net/sched/sch_api.c:1319 __tc_modify_qdisc net/sched/sch_api.c:1765 [inline] tc_modify_qdisc+0x1582/0x2140 net/sched/sch_api.c:1829 rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6967 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x830 net/socket.c:2630 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684 __sys_sendmsg net/socket.c:2716 [inline] __do_sys_sendmsg net/socket.c:2721 [inline] __se_sys_sendmsg net/socket.c:2719 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1beb98f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd1afcc778 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f1bebbe5fa0 RCX: 00007f1beb98f749 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000003 RBP: 00007f1beba13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1bebbe5fa0 R14: 00007f1bebbe5fa0 R15: 0000000000000003 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:nla_len include/net/netlink.h:1296 [inline] RIP: 0010:parse_attr net/sched/sch_netem.c:960 [inline] RIP: 0010:netem_quirk_chk+0x8a/0x740 net/sched/sch_netem.c:990 Code: 7c 24 60 49 c1 ef 03 43 c7 04 27 f1 f1 f1 f1 43 c7 44 27 13 f3 f3 f3 f3 43 c6 44 27 17 f3 e8 8d 68 67 f8 48 89 d8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 32 06 00 00 0f b7 03 83 c0 fc 44 0f b7 RSP: 0018:ffffc900032c7140 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88810ff73a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881b82ce000 RBP: ffffc900032c72b8 R08: ffff88810ff73a00 R09: 0000000000000002 R10: 00000000fffffff1 R11: ffffffff89589ab0 R12: dffffc0000000000 R13: ffffffff89589ab0 R14: ffffffff8f7d9580 R15: 1ffff92000658e34 FS: 000055558efa7500(0000) GS:ffff8882a9f35000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000100 CR3: 0000000114760000 CR4: 00000000000006f0 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 24 60 and $0x60,%al 2: 49 c1 ef 03 shr $0x3,%r15 6: 43 c7 04 27 f1 f1 f1 movl $0xf1f1f1f1,(%r15,%r12,1) d: f1 e: 43 c7 44 27 13 f3 f3 movl $0xf3f3f3f3,0x13(%r15,%r12,1) 15: f3 f3 17: 43 c6 44 27 17 f3 movb $0xf3,0x17(%r15,%r12,1) 1d: e8 8d 68 67 f8 call 0xf86768af 22: 48 89 d8 mov %rbx,%rax 25: 48 c1 e8 03 shr $0x3,%rax * 29: 42 0f b6 04 20 movzbl (%rax,%r12,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 32 06 00 00 jne 0x668 36: 0f b7 03 movzwl (%rbx),%eax 39: 83 c0 fc add $0xfffffffc,%eax 3c: 44 rex.R 3d: 0f .byte 0xf 3e: b7 .byte 0xb7 *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@syzkaller.appspotmail.com --- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at syzkaller@googlegroups.com.