linux/net/rxrpc
David Howells f0308fb070 rxrpc: Fix possible NULL pointer access in ICMP handling
If an ICMP packet comes in on the UDP socket backing an AF_RXRPC socket as
the UDP socket is being shut down, rxrpc_error_report() may get called to
deal with it after sk_user_data on the UDP socket has been cleared, leading
to a NULL pointer access when this local endpoint record gets accessed.

Fix this by just returning immediately if sk_user_data was NULL.

The oops looks like the following:

#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
...
RIP: 0010:rxrpc_error_report+0x1bd/0x6a9
...
Call Trace:
 ? sock_queue_err_skb+0xbd/0xde
 ? __udp4_lib_err+0x313/0x34d
 __udp4_lib_err+0x313/0x34d
 icmp_unreach+0x1ee/0x207
 icmp_rcv+0x25b/0x28f
 ip_protocol_deliver_rcu+0x95/0x10e
 ip_local_deliver+0xe9/0x148
 __netif_receive_skb_one_core+0x52/0x6e
 process_backlog+0xdc/0x177
 net_rx_action+0xf9/0x270
 __do_softirq+0x1b6/0x39a
 ? smpboot_register_percpu_thread+0xce/0xce
 run_ksoftirqd+0x1d/0x42
 smpboot_thread_fn+0x19e/0x1b3
 kthread+0xf1/0xf6
 ? kthread_delayed_work_timer_fn+0x83/0x83
 ret_from_fork+0x24/0x30

Fixes: 17926a7932 ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Reported-by: syzbot+611164843bd48cc2190c@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-11 21:20:23 -07:00
..
af_rxrpc.c rxrpc: Fix lack of conn cleanup when local endpoint is cleaned up [ver #2] 2019-08-30 15:06:52 -07:00
ar-internal.h rxrpc: Fix call crypto state cleanup 2019-10-07 11:05:05 +01:00
call_accept.c rxrpc: Fix call crypto state cleanup 2019-10-07 11:05:05 +01:00
call_event.c rxrpc: Use the tx-phase skb flag to simplify tracing 2019-08-27 10:04:18 +01:00
call_object.c rxrpc: Fix call crypto state cleanup 2019-10-07 11:05:05 +01:00
conn_client.c rxrpc: Fix call crypto state cleanup 2019-10-07 11:05:05 +01:00
conn_event.c rxrpc: Use the tx-phase skb flag to simplify tracing 2019-08-27 10:04:18 +01:00
conn_object.c rxrpc: Fix trace-after-put looking at the put connection record 2019-10-07 11:05:05 +01:00
conn_service.c rxrpc: Fix trace-after-put looking at the put connection record 2019-10-07 11:05:05 +01:00
input.c rxrpc: Fix misplaced traceline 2019-09-05 00:24:58 +02:00
insecure.c rxrpc: Fix -Wframe-larger-than= warnings from on-stack crypto 2019-07-30 10:32:35 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
key.c Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
local_event.c rxrpc: Use the tx-phase skb flag to simplify tracing 2019-08-27 10:04:18 +01:00
local_object.c rxrpc: Fix lack of conn cleanup when local endpoint is cleaned up [ver #2] 2019-08-30 15:06:52 -07:00
Makefile
misc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
net_ns.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
output.c rxrpc: Use the tx-phase skb flag to simplify tracing 2019-08-27 10:04:18 +01:00
peer_event.c rxrpc: Fix possible NULL pointer access in ICMP handling 2019-10-11 21:20:23 -07:00
peer_object.c rxrpc: rxrpc_peer needs to hold a ref on the rxrpc_local record 2019-10-07 11:05:05 +01:00
proc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
protocol.h rxrpc: Improve jumbo packet counting 2019-08-27 09:48:37 +01:00
recvmsg.c rxrpc: Fix call crypto state cleanup 2019-10-07 11:05:05 +01:00
rxkad.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-02 11:20:17 -07:00
security.c Keyrings namespacing 2019-07-08 19:36:47 -07:00
sendmsg.c rxrpc: Fix call crypto state cleanup 2019-10-07 11:05:05 +01:00
skbuff.c rxrpc: Use skb_unshare() rather than skb_cow_data() 2019-08-27 10:13:46 +01:00
sysctl.c proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
utils.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00