On Sun, Apr 8, 2018 at 9:29 PM, Eric Biggers <ebiggers3@xxxxxxxxx> wrote: >> syzkaller has found reproducer for the following crash on >> fba961ab29e5ffb055592442808bb0f7962e05da >> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.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 >> >> >> Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable >> >> ============================= >> WARNING: suspicious RCU usage >> 4.15.0-rc4+ #164 Not tainted >> ----------------------------- >> ./include/net/inet_sock.h:136 suspicious rcu_dereference_check() usage! >> >> other info that might help us debug this: >> >> >> rcu_scheduler_active = 2, debug_locks = 1 >> 1 lock held by syzkaller667189/5780: >> #0: (sk_lock-AF_INET6){+.+.}, at: [<000000008d7d4e62>] lock_sock >> include/net/sock.h:1462 [inline] >> #0: (sk_lock-AF_INET6){+.+.}, at: [<000000008d7d4e62>] >> do_ipv6_setsockopt.isra.9+0x23d/0x38f0 net/ipv6/ipv6_sockglue.c:167 >> >> stack backtrace: >> CPU: 0 PID: 5780 Comm: syzkaller667189 Not tainted 4.15.0-rc4+ #164 >> 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 >> lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4585 >> ireq_opt_deref include/net/inet_sock.h:135 [inline] >> inet_csk_route_req+0x824/0xca0 net/ipv4/inet_connection_sock.c:544 >> dccp_v4_send_response+0xa7/0x640 net/dccp/ipv4.c:485 >> dccp_v4_conn_request+0x9ee/0x11b0 net/dccp/ipv4.c:633 >> dccp_v6_conn_request+0xd30/0x1350 net/dccp/ipv6.c:317 >> dccp_rcv_state_process+0x574/0x1620 net/dccp/input.c:612 >> dccp_v4_do_rcv+0xeb/0x160 net/dccp/ipv4.c:682 >> dccp_v6_do_rcv+0x81a/0x9b0 net/dccp/ipv6.c:578 >> sk_backlog_rcv include/net/sock.h:907 [inline] >> __release_sock+0x124/0x360 net/core/sock.c:2274 >> release_sock+0xa4/0x2a0 net/core/sock.c:2789 >> do_ipv6_setsockopt.isra.9+0x50f/0x38f0 net/ipv6/ipv6_sockglue.c:898 >> ipv6_setsockopt+0xd7/0x150 net/ipv6/ipv6_sockglue.c:922 >> dccp_setsockopt+0x85/0xd0 net/dccp/proto.c:573 >> sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978 >> SYSC_setsockopt net/socket.c:1821 [inline] >> SyS_setsockopt+0x189/0x360 net/socket.c:1800 >> entry_SYSCALL_64_fastpath+0x1f/0x96 >> RIP: 0033:0x445ec9 >> RSP: 002b:00007fa001b58db8 EFLAGS: 00000297 ORIG_RAX: 0000000000000036 >> RAX: ffffffffffffffda RBX: 00000000006dbc24 RCX: 0000000000445ec9 >> RDX: 0000000000000020 RSI: 0000000000000029 RDI: 0000000000000004 >> RBP: 00000000006dbc20 R08: 0000000000000020 R09: 0000000000000000 >> R10: 000000002030a000 R11: 0000000000000297 R12: 0000000000000000 >> R13: 00007fff809eec1f R14: 00007fa001b599c0 R15: 0000000000000001 >> >> ============================= >> WARNING: suspicious RCU usage >> 4.15.0-rc4+ #164 Not tainted >> ----------------------------- >> ./include/net/inet_sock.h:136 suspicious rcu_dereference_check() usage! >> >> other info that might help us debug this: >> >> >> rcu_scheduler_active = 2, debug_locks = 1 >> 1 lock held by syzkaller667189/5780: >> #0: (sk_lock-AF_INET6){+.+.}, at: [<000000008d7d4e62>] lock_sock >> include/net/sock.h:1462 [inline] >> #0: (sk_lock-AF_INET6){+.+.}, at: [<000000008d7d4e62>] >> do_ipv6_setsockopt.isra.9+0x23d/0x38f0 net/ipv6/ipv6_sockglue.c:167 >> >> stack backtrace: >> CPU: 0 PID: 5780 Comm: syzkaller667189 Not tainted 4.15.0-rc4+ #164 >> 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 >> lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4585 >> ireq_opt_deref include/net/inet_sock.h:135 [inline] >> dccp_v4_send_response+0x4b0/0x640 net/dccp/ipv4.c:496 >> dccp_v4_conn_request+0x9ee/0x11b0 net/dccp/ipv4.c:633 >> dccp_v6_conn_request+0xd30/0x1350 net/dccp/ipv6.c:317 >> dccp_rcv_state_process+0x574/0x1620 net/dccp/input.c:612 >> dccp_v4_do_rcv+0xeb/0x160 net/dccp/ipv4.c:682 >> dccp_v6_do_rcv+0x81a/0x9b0 net/dccp/ipv6.c:578 >> sk_backlog_rcv include/net/sock.h:907 [inline] >> __release_sock+0x124/0x360 net/core/sock.c:2274 >> release_sock+0xa4/0x2a0 net/core/sock.c:2789 >> do_ipv6_setsockopt.isra.9+0x50f/0x38f0 net/ipv6/ipv6_sockglue.c:898 >> ipv6_setsockopt+0xd7/0x150 net/ipv6/ipv6_sockglue.c:922 >> dccp_setsockopt+0x85/0xd0 net/dccp/proto.c:573 >> sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2978 >> SYSC_setsockopt net/socket.c:1821 [inline] >> SyS_setsockopt+0x189/0x360 net/socket.c:1800 >> entry_SYSCALL_64_fastpath+0x1f/0x96 >> RIP: 0033:0x445ec9 >> RSP: 002b:00007fa001b58db8 EFLAGS: 00000297 ORIG_RAX: 0000000000000036 >> RAX: ffffffffffffffda RBX: 00000000006dbc24 RCX: 0000000000445ec9 >> RDX: 0000000000000020 RSI: 0000000000000029 RDI: 0000000000000004 >> RBP: 00000000006dbc20 R08: 0000000000000020 R09: 0000000000000000 >> R10: 000000002030a000 R11: 0000000000000297 R12: 0000000000000000 >> R13: 00007fff809eec1f R14: 00007fa001b599c0 R15: 0000000000000001 > > syzbot stopped hitting this for some reason, but the bug is still there. > Here's a simplified reproducer that works on Linus' tree as of today: > > #include <linux/in.h> > #include <stdlib.h> > #include <sys/socket.h> > #include <unistd.h> > > int main() > { > int is_parent = (fork() != 0); > for (;;) { > int fd = socket(AF_INET, SOCK_DCCP, 0); > struct sockaddr_in addr = { > .sin_family = AF_INET, > .sin_port = htobe16(0x4e23), > }; > if (is_parent) { > connect(fd, (void *)&addr, sizeof(addr)); > } else { > bind(fd, (void *)&addr, sizeof(addr)); > listen(fd, 100); > setsockopt(fd, 0, 0xFFFF, NULL, 0); > } > close(fd); > } > } Still happens on the current upstream HEAD e6506eb241871d68647c53cb6d0a16299550ae97. -- To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
