David Howells 99f0eae653 rxrpc: Fix oops in tracepoint ... If the rxrpc_eproto tracepoint is enabled, an oops will be cause by the trace line that rxrpc_extract_header() tries to emit when a protocol error occurs (typically because the packet is short) because the call argument is NULL. Fix this by using ?: to assume 0 as the debug_id if call is NULL. This can then be induced by: echo -e '\0\0\0\0\0\0\0\0' | ncat -4u --send-only <addr> 20001 where addr has the following program running on it: #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <arpa/inet.h> #include <linux/rxrpc.h> int main(void) { struct sockaddr_rxrpc srx; int fd; memset(&srx, 0, sizeof(srx)); srx.srx_family = AF_RXRPC; srx.srx_service = 0; srx.transport_type = AF_INET; srx.transport_len = sizeof(srx.transport.sin); srx.transport.sin.sin_family = AF_INET; srx.transport.sin.sin_port = htons(0x4e21); fd = socket(AF_RXRPC, SOCK_DGRAM, AF_INET6); bind(fd, (struct sockaddr *)&srx, sizeof(srx)); sleep(20); return 0; } It results in the following oops. BUG: kernel NULL pointer dereference, address: 0000000000000340 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page ... RIP: 0010:trace_event_raw_event_rxrpc_rx_eproto+0x47/0xac ... Call Trace: <IRQ> rxrpc_extract_header+0x86/0x171 ? rcu_read_lock_sched_held+0x5d/0x63 ? rxrpc_new_skb+0xd4/0x109 rxrpc_input_packet+0xef/0x14fc ? rxrpc_input_data+0x986/0x986 udp_queue_rcv_one_skb+0xbf/0x3d0 udp_unicast_rcv_skb.isra.8+0x64/0x71 ip_protocol_deliver_rcu+0xe4/0x1b4 ip_local_deliver+0xf0/0x154 __netif_receive_skb_one_core+0x50/0x6c netif_receive_skb_internal+0x26b/0x2e9 napi_gro_receive+0xf8/0x1da rtl8169_poll+0x303/0x4c4 net_rx_action+0x10e/0x333 __do_softirq+0x1a5/0x38f irq_exit+0x54/0xc4 do_IRQ+0xda/0xf8 common_interrupt+0xf/0xf </IRQ> ... ? cpuidle_enter_state+0x23c/0x34d cpuidle_enter+0x2a/0x36 do_idle+0x163/0x1ea cpu_startup_entry+0x1d/0x1f start_secondary+0x157/0x172 secondary_startup_64+0xa4/0xb0 Fixes: a25e21f0bc ("rxrpc, afs: Use debug_ids rather than pointers in traces") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2019-07-02 15:29:57 -07:00
..
events	rxrpc: Fix oops in tracepoint	2019-07-02 15:29:57 -07:00
bpf_probe.h	bpf: add writable context for raw tracepoints	2019-04-26 19:04:19 -07:00
define_trace.h	tracing: introduce TRACE_EVENT_NOP()	2019-04-08 09:22:51 -04:00
perf.h
syscall.h
trace_events.h