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+c0ea2226f77a42936...@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 <linux/filter.h> #include <linux/in.h> #include <sys/socket.h> 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); } }