From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1517527816; cv=none; d=google.com; s=arc-20160816; b=AmYCgMWzUu+7GsjTne+C2bOaA3UDWHtS2ywCySnIRC8/0XspaSiRf62H0sAEuzyTRm RGXOVhEs7rLD1F6uqXTLqsjg0oavTu+TBkYBc++ADQtrqfiUizj2g5rPIyf/dNJg7Xlg Q8F+Unj+IPzd3+1cw7Ut70IJ4oKWePRkxAUsTM919vjiq7WQ683FUQMChMfL5n9AuGQj Bot3v1kyXCVyhXBmqr/8RmYuxyWE2qYB8FZFAX/Vu2SDmWsbH9xntqEOPLKqEOuya3qm xr/ZUCbq7kKgTqPaaVcLZIwn7G5PbOxt+1yilfe3kzF4/SA3lQqTOehZS4nvh4ua9mT1 1m3g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:dkim-signature :arc-authentication-results; bh=/mXTsFUiOXiMf0Rp/PH3TVdHJAltuS2FrYHo29036YQ=; b=TlIl+8ay57O41dSBHeMSeZV0LYJsrbrPv+QW9oCQxDX+DJFjKkY77A2IUv1bwzxBHV UsVpjR6iCgwBOXFBEUuuGIwRODLB1dhjd3rUIKg2UESASd605bwoMCH5VA3RGF2f5hVJ Qa0rVEPeLx2nB9WKG2snZ7q/3R2KF0Y0KU9BYC6f2/7lKi1bdRpZlQ9rEMUqKldJ/9E9 dBNXAl/iUji8gx4rNwpoFn8l1BDTtv8Z9AfCGzqm8XOEobhnh0KfYjcyXov1TSBHRqDt lV/KJfsJgAs8K9sqkZHx5/9mLdRl003v+IUJxeuTRVMcet1yTqIuro3807tlS/9IWdgZ OrCA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=GxG9rcd9; spf=pass (google.com: domain of ebiggers3@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=ebiggers3@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=GxG9rcd9; spf=pass (google.com: domain of ebiggers3@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=ebiggers3@gmail.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gmail.com X-Google-Smtp-Source: AH8x227b20zv8l9+/Zi00YiNTbXGCFDNd8oUP83LubORVIuvzuZT3ocK1bw2v/j4mvj85cHVRQECUQ== Date: Thu, 1 Feb 2018 15:30:12 -0800 From: Eric Biggers To: syzbot Cc: adobriyan@gmail.com, davem@davemloft.net, gregkh@linuxfoundation.org, kraig@google.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pombredanne@nexb.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de Subject: Re: WARNING in reuseport_add_sock Message-ID: <20180201233012.fgcve3ohufcspb2c@gmail.com> References: <94eb2c1fcf4cdda26b05629d08d4@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <94eb2c1fcf4cdda26b05629d08d4@google.com> User-Agent: NeoMutt/20170609 (1.8.3) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1589433054887734562?= X-GMAIL-MSGID: =?utf-8?q?1591243247671500884?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Fri, Jan 12, 2018 at 03:58:01PM -0800, syzbot wrote: > Hello, > > syzkaller hit the following crash on > 30a7acd573899fd8b8ac39236eff6468b195ac7d > git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached > Raw console output is attached. > C reproducer is attached > syzkaller reproducer is attached. See https://goo.gl/kgGztJ > for information about syzkaller reproducers > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+c0ea2226f77a42936bf7@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > ------------[ cut here ]------------ > socket already in reuseport group > WARNING: CPU: 0 PID: 3496 at net/core/sock_reuseport.c:119 > reuseport_add_sock+0x742/0x9b0 net/core/sock_reuseport.c:117 > Kernel panic - not syncing: panic_on_warn set ... > > CPU: 0 PID: 3496 Comm: syzkaller869503 Not tainted 4.15.0-rc6+ #245 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x257 lib/dump_stack.c:53 > panic+0x1e4/0x41c kernel/panic.c:183 > __warn+0x1dc/0x200 kernel/panic.c:547 > report_bug+0x211/0x2d0 lib/bug.c:184 > fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 > fixup_bug arch/x86/kernel/traps.c:247 [inline] > do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 > do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 > invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1079 > RIP: 0010:reuseport_add_sock+0x742/0x9b0 net/core/sock_reuseport.c:117 > RSP: 0018:ffff8801bf5f7968 EFLAGS: 00010286 > RAX: dffffc0000000008 RBX: ffff8801bf4905c0 RCX: ffffffff8159d9de > RDX: 0000000000000000 RSI: 1ffff10037ebeee8 RDI: 0000000000000293 > RBP: ffff8801bf5f7b00 R08: 1ffff10037ebeeaa R09: 0000000000000000 > R10: ffff8801bf5f7820 R11: 0000000000000000 R12: 1ffff10037ebef37 > R13: ffff8801bf47b930 R14: ffff8801bf5f7ad8 R15: 1ffff10037ebef3b > inet_reuseport_add_sock net/ipv4/inet_hashtables.c:456 [inline] > __inet_hash+0x767/0xb90 net/ipv4/inet_hashtables.c:477 > inet_hash+0x61/0x90 net/ipv4/inet_hashtables.c:501 > inet_csk_listen_start+0x38f/0x460 net/ipv4/inet_connection_sock.c:885 > inet_listen+0x19a/0x440 net/ipv4/af_inet.c:228 > SYSC_listen net/socket.c:1483 [inline] > SyS_listen+0x1aa/0x350 net/socket.c:1469 > entry_SYSCALL_64_fastpath+0x23/0x9a > RIP: 0033:0x445639 > RSP: 002b:00007f2966197db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000032 > RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 0000000000445639 > RDX: 0000000000445639 RSI: 0000000000000000 RDI: 0000000000000006 > RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007ffc328a273f R14: 00007f29661989c0 R15: 0000000000000008 > Dumping ftrace buffer: > (ftrace buffer empty) > Kernel Offset: disabled > Rebooting in 86400 seconds.. > Still happens. Here's a simplified reproducer: #include #include #include int main() { struct sock_filter filt = { .code = 6 }; struct sock_fprog prog = { .len = 1, .filter = &filt }; struct sockaddr_in addr = { .sin_family = AF_INET, .sin_port = htobe16(20000), }; for (;;) { int fd = socket(AF_INET, SOCK_STREAM, 0); setsockopt(fd, IPPROTO_TCP, IP_TRANSPARENT, &(int){ 1 }, 4); setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &(int){ 1 }, 4); setsockopt(fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_CBPF, &prog, sizeof(prog)); bind(fd, (void *)&addr, sizeof(addr)); listen(fd, 0); } }