linux/net
Eric Dumazet 12d94a8049 ipv6: fix NULL dereference in ip6_route_dev_notify()
Based on a syzkaller report [1], I found that a per cpu allocation
failure in snmp6_alloc_dev() would then lead to NULL dereference in
ip6_route_dev_notify().

It seems this is a very old bug, thus no Fixes tag in this submission.

Let's add in6_dev_put_clear() helper, as we will probably use
it elsewhere (once available/present in net-next)

[1]
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 17294 Comm: syz-executor6 Not tainted 4.13.0-rc2+ #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88019f456680 task.stack: ffff8801c6e58000
RIP: 0010:__read_once_size include/linux/compiler.h:250 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:26 [inline]
RIP: 0010:refcount_sub_and_test+0x7d/0x1b0 lib/refcount.c:178
RSP: 0018:ffff8801c6e5f1b0 EFLAGS: 00010202
RAX: 0000000000000037 RBX: dffffc0000000000 RCX: ffffc90005d25000
RDX: ffff8801c6e5f218 RSI: ffffffff82342bbf RDI: 0000000000000001
RBP: ffff8801c6e5f240 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10038dcbe37
R13: 0000000000000006 R14: 0000000000000001 R15: 00000000000001b8
FS:  00007f21e0429700(0000) GS:ffff8801dc100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001ddbc22000 CR3: 00000001d632b000 CR4: 00000000001426e0
DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 refcount_dec_and_test+0x1a/0x20 lib/refcount.c:211
 in6_dev_put include/net/addrconf.h:335 [inline]
 ip6_route_dev_notify+0x1c9/0x4a0 net/ipv6/route.c:3732
 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x51/0x90 net/core/dev.c:1678
 call_netdevice_notifiers net/core/dev.c:1694 [inline]
 rollback_registered_many+0x91c/0xe80 net/core/dev.c:7107
 rollback_registered+0x1be/0x3c0 net/core/dev.c:7149
 register_netdevice+0xbcd/0xee0 net/core/dev.c:7587
 register_netdev+0x1a/0x30 net/core/dev.c:7669
 loopback_net_init+0x76/0x160 drivers/net/loopback.c:214
 ops_init+0x10a/0x570 net/core/net_namespace.c:118
 setup_net+0x313/0x710 net/core/net_namespace.c:294
 copy_net_ns+0x27c/0x580 net/core/net_namespace.c:418
 create_new_namespaces+0x425/0x880 kernel/nsproxy.c:107
 unshare_nsproxy_namespaces+0xae/0x1e0 kernel/nsproxy.c:206
 SYSC_unshare kernel/fork.c:2347 [inline]
 SyS_unshare+0x653/0xfa0 kernel/fork.c:2297
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x4512c9
RSP: 002b:00007f21e0428c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000718150 RCX: 00000000004512c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062020200
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b973d
R13: 00000000ffffffff R14: 000000002001d000 R15: 00000000000002dd
Code: 50 2b 34 82 c7 00 f1 f1 f1 f1 c7 40 04 04 f2 f2 f2 c7 40 08 f3 f3
f3 f3 e8 a1 43 39 ff 4c 89 f8 48 8b 95 70 ff ff ff 48 c1 e8 03 <0f> b6
0c 18 4c 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85
RIP: __read_once_size include/linux/compiler.h:250 [inline] RSP:
ffff8801c6e5f1b0
RIP: atomic_read arch/x86/include/asm/atomic.h:26 [inline] RSP:
ffff8801c6e5f1b0
RIP: refcount_sub_and_test+0x7d/0x1b0 lib/refcount.c:178 RSP:
ffff8801c6e5f1b0
---[ end trace e441d046c6410d31 ]---

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15 17:06:34 -07:00
..
6lowpan 6lowpan: Don't set IFF_NO_QUEUE 2017-04-12 22:02:40 +02:00
9p Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
802 net: introduce __skb_put_[zero, data, u8] 2017-06-20 13:30:14 -04:00
8021q net: add netlink_ext_ack argument to rtnl_link_ops.validate 2017-06-26 23:13:22 -04:00
appletalk networking: make skb_push & __skb_push return void pointers 2017-06-16 11:48:40 -04:00
atm net, atm: convert eg_cache_entry.use from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
ax25 net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t 2017-07-04 22:35:19 +01:00
batman-adv batman-adv: fix TT sync flag inconsistencies 2017-07-31 11:17:38 +02:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-07-05 12:31:59 -07:00
bpf bpf: Align packet data properly in program testing framework. 2017-05-02 11:46:28 -04:00
bridge net: bridge: fix dest lookup when vlan proto doesn't match 2017-07-14 08:19:23 -07:00
caif net: convert sock.sk_wmem_alloc from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
can networking: introduce and use skb_put_data() 2017-06-16 11:48:37 -04:00
ceph libceph: make RECOVERY_DELETES feature create a new interval 2017-08-01 16:46:45 +02:00
core bpf: fix two missing target_size settings in bpf_convert_ctx_access 2017-08-11 14:59:24 -07:00
dcb dcb: enforce minimum length on IEEE_APPS attribute 2017-05-21 13:42:33 -04:00
dccp dccp: purge write queue in dccp_destroy_sock() 2017-08-14 22:28:18 -07:00
decnet net, decnet: convert dn_fib_info.fib_clntref from atomic_t to refcount_t 2017-07-04 22:35:15 +01:00
dns_resolver
dsa net: dsa: ksz: fix skb freeing 2017-08-11 13:57:08 -07:00
ethernet networking: make skb_push & __skb_push return void pointers 2017-06-16 11:48:40 -04:00
hsr net: add netlink_ext_ack argument to rtnl_link_ops.newlink 2017-06-26 23:13:21 -04:00
ieee802154 net: add netlink_ext_ack argument to rtnl_link_ops.validate 2017-06-26 23:13:22 -04:00
ife
ipv4 tcp: fix possible deadlock in TCP stack vs BPF filter 2017-08-14 22:31:27 -07:00
ipv6 ipv6: fix NULL dereference in ip6_route_dev_notify() 2017-08-15 17:06:34 -07:00
ipx net, ipx: convert ipx_route.refcnt from atomic_t to refcount_t 2017-07-04 22:35:17 +01:00
irda Merge branch 'work.memdup_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-05 16:05:24 -07:00
iucv iucv: Convert sk_wmem_alloc accesses to refcount_t. 2017-07-03 02:31:22 -07:00
kcm net: convert sock.sk_wmem_alloc from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
key af_key: do not use GFP_KERNEL in atomic contexts 2017-08-14 22:18:12 -07:00
l2tp net, l2tp: convert l2tp_session.ref_count from atomic_t to refcount_t 2017-07-04 22:35:15 +01:00
l3mdev
lapb net, lapb: convert lapb_cb.refcnt from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
llc net, llc: convert llc_sap.refcnt from atomic_t to refcount_t 2017-07-04 22:35:15 +01:00
mac80211 mac80211: add api to start ba session timer expired flow 2017-08-09 09:49:42 +03:00
mac802154 net: Fix inconsistent teardown and release of private netdev state. 2017-06-07 15:53:24 -04:00
mpls mpls: fix uninitialized in_label var warning in mpls_getroute 2017-07-08 11:26:41 +01:00
ncsi networking: make skb_push & __skb_push return void pointers 2017-06-16 11:48:40 -04:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-07-20 16:33:39 -07:00
netlabel netlink: pass extended ACK struct to parsing functions 2017-04-13 13:58:22 -04:00
netlink net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
netrom net, netrom: convert nr_node.refcount from atomic_t to refcount_t 2017-07-04 22:35:17 +01:00
nfc NFC: Add sockaddr length checks before accessing sa_family in bind handlers 2017-06-23 00:38:31 +02:00
openvswitch openvswitch: fix potential out of bound access in parse_ct 2017-07-24 16:25:06 -07:00
packet packet: fix tp_reserve race in packet_set_ring 2017-08-10 09:52:12 -07:00
phonet net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
psample networking: make skb_put & friends return void pointers 2017-06-16 11:48:39 -04:00
qrtr networking: make skb_put & friends return void pointers 2017-06-16 11:48:39 -04:00
rds rds: Reintroduce statistics counting 2017-08-08 21:03:47 -07:00
rfkill net: rfkill: gpio: Switch to devm_acpi_dev_add_driver_gpios() 2017-06-13 11:07:51 +02:00
rose net: Work around lockdep limitation in sockets that use sockets 2017-03-09 18:23:27 -08:00
rxrpc net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
sched net/sched/hfsc: allocate tcf block for hfsc root class 2017-08-11 14:30:30 -07:00
sctp sctp: fix an array overflow when all ext chunks are set 2017-07-14 09:05:10 -07:00
smc net/smc: Add warning about remote memory exposure 2017-05-16 14:49:43 -04:00
strparser
sunrpc NFS client bugfixes for 4.13 2017-07-21 16:26:01 -07:00
switchdev net: switchdev: Change notifier chain to be atomic 2017-06-08 14:16:24 -04:00
tipc tipc: avoid inheriting msg_non_seq flag when message is returned 2017-08-14 11:20:36 -07:00
tls TLS: Fix length check in do_tls_getsockopt_tx() 2017-07-06 10:58:19 +01:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-07-05 12:31:59 -07:00
vmw_vsock net: manual clean code which call skb_put_[data:zero] 2017-06-20 13:30:15 -04:00
wimax
wireless netlink validation fixes for nl80211 2017-07-07 11:35:55 +01:00
x25 net, x25: convert x25_neigh.refcnt from atomic_t to refcount_t 2017-07-04 22:35:18 +01:00
xfrm net, xfrm: convert sec_path.refcnt from atomic_t to refcount_t 2017-07-04 22:35:18 +01:00
compat.c get_compat_bpf_fprog(): don't copyin field-by-field 2017-07-04 13:14:34 -04:00
Kconfig tls: kernel TLS support 2017-06-15 12:12:40 -04:00
Makefile tls: kernel TLS support 2017-06-15 12:12:40 -04:00
socket.c net/socket: fix type in assignment and trim long line 2017-07-24 14:17:01 -07:00
sysctl_net.c sysctl: Remove dead register_sysctl_root 2017-04-16 23:42:49 -05:00