linux/net/ipv6
Nikolay Aleksandrov 2cf750704b ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route
Since the commit below the ipmr/ip6mr rtnl_unicast() code uses the portid
instead of the previous dst_pid which was copied from in_skb's portid.
Since the skb is new the portid is 0 at that point so the packets are sent
to the kernel and we get scheduling while atomic or a deadlock (depending
on where it happens) by trying to acquire rtnl two times.
Also since this is RTM_GETROUTE, it can be triggered by a normal user.

Here's the sleeping while atomic trace:
[ 7858.212557] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[ 7858.212748] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0
[ 7858.212881] 2 locks held by swapper/0/0:
[ 7858.213013]  #0:  (((&mrt->ipmr_expire_timer))){+.-...}, at: [<ffffffff810fbbf5>] call_timer_fn+0x5/0x350
[ 7858.213422]  #1:  (mfc_unres_lock){+.....}, at: [<ffffffff8161e005>] ipmr_expire_process+0x25/0x130
[ 7858.213807] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc7+ #179
[ 7858.213934] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 7858.214108]  0000000000000000 ffff88005b403c50 ffffffff813a7804 0000000000000000
[ 7858.214412]  ffffffff81a1338e ffff88005b403c78 ffffffff810a4a72 ffffffff81a1338e
[ 7858.214716]  000000000000026c 0000000000000000 ffff88005b403ca8 ffffffff810a4b9f
[ 7858.215251] Call Trace:
[ 7858.215412]  <IRQ>  [<ffffffff813a7804>] dump_stack+0x85/0xc1
[ 7858.215662]  [<ffffffff810a4a72>] ___might_sleep+0x192/0x250
[ 7858.215868]  [<ffffffff810a4b9f>] __might_sleep+0x6f/0x100
[ 7858.216072]  [<ffffffff8165bea3>] mutex_lock_nested+0x33/0x4d0
[ 7858.216279]  [<ffffffff815a7a5f>] ? netlink_lookup+0x25f/0x460
[ 7858.216487]  [<ffffffff8157474b>] rtnetlink_rcv+0x1b/0x40
[ 7858.216687]  [<ffffffff815a9a0c>] netlink_unicast+0x19c/0x260
[ 7858.216900]  [<ffffffff81573c70>] rtnl_unicast+0x20/0x30
[ 7858.217128]  [<ffffffff8161cd39>] ipmr_destroy_unres+0xa9/0xf0
[ 7858.217351]  [<ffffffff8161e06f>] ipmr_expire_process+0x8f/0x130
[ 7858.217581]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.217785]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.217990]  [<ffffffff810fbc95>] call_timer_fn+0xa5/0x350
[ 7858.218192]  [<ffffffff810fbbf5>] ? call_timer_fn+0x5/0x350
[ 7858.218415]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.218656]  [<ffffffff810fde10>] run_timer_softirq+0x260/0x640
[ 7858.218865]  [<ffffffff8166379b>] ? __do_softirq+0xbb/0x54f
[ 7858.219068]  [<ffffffff816637c8>] __do_softirq+0xe8/0x54f
[ 7858.219269]  [<ffffffff8107a948>] irq_exit+0xb8/0xc0
[ 7858.219463]  [<ffffffff81663452>] smp_apic_timer_interrupt+0x42/0x50
[ 7858.219678]  [<ffffffff816625bc>] apic_timer_interrupt+0x8c/0xa0
[ 7858.219897]  <EOI>  [<ffffffff81055f16>] ? native_safe_halt+0x6/0x10
[ 7858.220165]  [<ffffffff810d64dd>] ? trace_hardirqs_on+0xd/0x10
[ 7858.220373]  [<ffffffff810298e3>] default_idle+0x23/0x190
[ 7858.220574]  [<ffffffff8102a20f>] arch_cpu_idle+0xf/0x20
[ 7858.220790]  [<ffffffff810c9f8c>] default_idle_call+0x4c/0x60
[ 7858.221016]  [<ffffffff810ca33b>] cpu_startup_entry+0x39b/0x4d0
[ 7858.221257]  [<ffffffff8164f995>] rest_init+0x135/0x140
[ 7858.221469]  [<ffffffff81f83014>] start_kernel+0x50e/0x51b
[ 7858.221670]  [<ffffffff81f82120>] ? early_idt_handler_array+0x120/0x120
[ 7858.221894]  [<ffffffff81f8243f>] x86_64_start_reservations+0x2a/0x2c
[ 7858.222113]  [<ffffffff81f8257c>] x86_64_start_kernel+0x13b/0x14a

Fixes: 2942e90050 ("[RTNETLINK]: Use rtnl_unicast() for rtnetlink unicasts")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-25 23:41:39 -04:00
..
ila ila: Fix checksum neutral mapping 2016-06-15 21:40:00 -07:00
netfilter netfilter: nft_chain_route: re-route before skb is queued to userspace 2016-09-06 18:02:37 +02:00
addrconf_core.c
addrconf.c ipv6: addrconf: fix dev refcont leak when DAD failed 2016-09-06 14:17:49 -07:00
addrlabel.c
af_inet6.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-07-29 17:38:46 -07:00
ah6.c
anycast.c
calipso.c calipso: fix resource leak on calipso_genopt failure 2016-08-13 14:56:17 -07:00
datagram.c sock: propagate __sock_cmsg_send() error 2016-05-16 13:46:23 -04:00
esp6.c
exthdrs_core.c ipv6: constify the skb pointer of ipv6_find_tlv(). 2016-06-27 15:06:15 -04:00
exthdrs_offload.c
exthdrs.c Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux into next 2016-07-07 10:15:34 +10:00
fib6_rules.c net: Add l3mdev rule 2016-06-08 11:36:02 -07:00
fou6.c fou: add Kconfig options for IPv6 support 2016-05-29 22:24:21 -07:00
icmp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-06-30 05:03:36 -04:00
inet6_connection_sock.c soreuseport: fast reuseport TCP socket selection 2016-02-11 03:54:15 -05:00
inet6_hashtables.c net: rename NET_{ADD|INC}_STATS_BH() 2016-04-27 22:48:24 -04:00
ip6_checksum.c ipv6: fix checksum annotation in udp6_csum_init 2016-06-14 15:26:42 -04:00
ip6_fib.c ipv6: Fix mem leak in rt6i_pcpu 2016-07-05 14:09:23 -07:00
ip6_flowlabel.c ipv6: add new struct ipcm6_cookie 2016-05-03 16:08:14 -04:00
ip6_gre.c ip6_gre: fix flowi6_proto value in ip6gre_xmit_other() 2016-09-24 09:44:31 -04:00
ip6_icmp.c ipv6: icmp: add a force_saddr param to icmp6_send() 2016-06-18 22:11:38 -07:00
ip6_input.c net: vrf: ipv6 support for local traffic to local addresses 2016-06-08 00:25:38 -07:00
ip6_offload.c ip4ip6: Support for GSO/GRO 2016-05-20 18:03:17 -04:00
ip6_offload.h udp: Add GRO functions to UDP socket 2016-04-07 16:53:29 -04:00
ip6_output.c net: vrf: Implement get_saddr for IPv6 2016-06-17 21:25:29 -07:00
ip6_tunnel.c ipv6: Don't unset flowi6_proto in ipxip6_tnl_xmit() 2016-09-01 23:41:24 -07:00
ip6_udp_tunnel.c ip_tunnel: add support for setting flow label via collect metadata 2016-03-11 15:14:26 -05:00
ip6_vti.c vti6: fix input path 2016-09-21 10:09:14 +02:00
ip6mr.c ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route 2016-09-25 23:41:39 -04:00
ipcomp6.c
ipv6_sockglue.c Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux into next 2016-07-07 10:15:34 +10:00
Kconfig fou: fix IPv6 Kconfig options 2016-05-31 14:07:49 -07:00
Makefile Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux into next 2016-07-07 10:15:34 +10:00
mcast_snoop.c
mcast.c mld, igmp: Fix reserved tailroom calculation 2016-03-03 15:41:07 -05:00
mip6.c
ndisc.c ipv6: export several functions 2016-06-15 20:41:23 -07:00
netfilter.c
output_core.c
ping.c ipv6: release dst in ping_v6_sendmsg 2016-09-06 12:54:17 -07:00
proc.c
protocol.c
raw.c ipv6: use TOS marks from sockets for routing decision 2016-06-11 15:33:26 -07:00
reassembly.c ipv6: rename IP6_INC_STATS_BH() 2016-04-27 22:48:24 -04:00
route.c ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route 2016-09-25 23:41:39 -04:00
sit.c sit: support MPLS over IPv4 2016-07-09 17:45:56 -04:00
syncookies.c net: rename NET_{ADD|INC}_STATS_BH() 2016-04-27 22:48:24 -04:00
sysctl_net_ipv6.c calipso: Add a label cache. 2016-06-27 15:06:17 -04:00
tcp_ipv6.c tcp: properly scale window in tcp_v[46]_reqsk_send_ack() 2016-08-23 16:55:49 -07:00
tcpv6_offload.c
tunnel6.c
udp_impl.h
udp_offload.c gso: Remove arbitrary checks for unsupported GSO 2016-05-20 18:03:15 -04:00
udp.c udp: get rid of SLAB_DESTROY_BY_RCU allocations 2016-08-23 17:46:17 -07:00
udplite.c udp: get rid of SLAB_DESTROY_BY_RCU allocations 2016-08-23 17:46:17 -07:00
xfrm6_input.c vti6: fix input path 2016-09-21 10:09:14 +02:00
xfrm6_mode_beet.c
xfrm6_mode_ro.c
xfrm6_mode_transport.c
xfrm6_mode_tunnel.c
xfrm6_output.c
xfrm6_policy.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec 2016-09-08 13:12:37 -07:00
xfrm6_protocol.c
xfrm6_state.c
xfrm6_tunnel.c vti6: fix input path 2016-09-21 10:09:14 +02:00