linux/net
Eric Dumazet db3fa27102 ipv6/addrconf: fix potential NULL deref in inet6_set_link_af()
__in6_dev_get(dev) called from inet6_set_link_af() can return NULL.

The needed check has been recently removed, let's add it back.

While do_setlink() does call validate_linkmsg() :
...
err = validate_linkmsg(dev, tb); /* OK at this point */
...

It is possible that the following call happening before the
->set_link_af() removes IPv6 if MTU is less than 1280 :

if (tb[IFLA_MTU]) {
    err = dev_set_mtu_ext(dev, nla_get_u32(tb[IFLA_MTU]), extack);
    if (err < 0)
          goto errout;
    status |= DO_SETLINK_MODIFIED;
}
...

if (tb[IFLA_AF_SPEC]) {
   ...
   err = af_ops->set_link_af(dev, af);
      ->inet6_set_link_af() // CRASH because idev is NULL

Please note that IPv4 is immune to the bug since inet_set_link_af() does :

struct in_device *in_dev = __in_dev_get_rcu(dev);
if (!in_dev)
    return -EAFNOSUPPORT;

This problem has been mentioned in commit cf7afbfeb8 ("rtnl: make
link af-specific updates atomic") changelog :

    This method is not fail proof, while it is currently sufficient
    to make set_link_af() inerrable and thus 100% atomic, the
    validation function method will not be able to detect all error
    scenarios in the future, there will likely always be errors
    depending on states which are f.e. not protected by rtnl_mutex
    and thus may change between validation and setting.

IPv6: ADDRCONF(NETDEV_CHANGE): lo: link becomes ready
general protection fault, probably for non-canonical address 0xdffffc0000000056: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000002b0-0x00000000000002b7]
CPU: 0 PID: 9698 Comm: syz-executor712 Not tainted 5.5.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:inet6_set_link_af+0x66e/0xae0 net/ipv6/addrconf.c:5733
Code: 38 d0 7f 08 84 c0 0f 85 20 03 00 00 48 8d bb b0 02 00 00 45 0f b6 64 24 04 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 1a 03 00 00 44 89 a3 b0 02 00
RSP: 0018:ffffc90005b06d40 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff86df39a6
RDX: 0000000000000056 RSI: ffffffff86df3e74 RDI: 00000000000002b0
RBP: ffffc90005b06e70 R08: ffff8880a2ac0380 R09: ffffc90005b06db0
R10: fffff52000b60dbe R11: ffffc90005b06df7 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880a1fcc424 R15: dffffc0000000000
FS:  0000000000c46880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f0494ca0d0 CR3: 000000009e4ac000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 do_setlink+0x2a9f/0x3720 net/core/rtnetlink.c:2754
 rtnl_group_changelink net/core/rtnetlink.c:3103 [inline]
 __rtnl_newlink+0xdd1/0x1790 net/core/rtnetlink.c:3257
 rtnl_newlink+0x69/0xa0 net/core/rtnetlink.c:3377
 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:672
 ____sys_sendmsg+0x753/0x880 net/socket.c:2343
 ___sys_sendmsg+0x100/0x170 net/socket.c:2397
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430
 __do_sys_sendmsg net/socket.c:2439 [inline]
 __se_sys_sendmsg net/socket.c:2437 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4402e9
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffd62fbcf8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004402e9
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000008 R09: 00000000004002c8
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000401b70
R13: 0000000000401c00 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace cfa7664b8fdcdff3 ]---
RIP: 0010:inet6_set_link_af+0x66e/0xae0 net/ipv6/addrconf.c:5733
Code: 38 d0 7f 08 84 c0 0f 85 20 03 00 00 48 8d bb b0 02 00 00 45 0f b6 64 24 04 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e 1a 03 00 00 44 89 a3 b0 02 00
RSP: 0018:ffffc90005b06d40 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff86df39a6
RDX: 0000000000000056 RSI: ffffffff86df3e74 RDI: 00000000000002b0
RBP: ffffc90005b06e70 R08: ffff8880a2ac0380 R09: ffffc90005b06db0
R10: fffff52000b60dbe R11: ffffc90005b06df7 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880a1fcc424 R15: dffffc0000000000
FS:  0000000000c46880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000004 CR3: 000000009e4ac000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fixes: 7dc2bccab0 ("Validate required parameters in inet6_validate_link_af")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Bisected-and-reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-07 18:43:23 +01:00
..
6lowpan
9p 9p pull request for inclusion in 5.4 2019-09-27 15:10:34 -07:00
802 treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
8021q Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-09 12:13:43 -08:00
appletalk appletalk: enforce CAP_NET_RAW for raw sockets 2019-09-24 16:37:18 +02:00
atm proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
ax25 net: Make sock protocol value checks more specific 2020-01-09 18:41:40 -08:00
batman-adv Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2020-01-19 22:10:04 +01:00
bluetooth Bluetooth: Fix race condition in hci_release_sock() 2020-01-26 10:34:17 +02:00
bpf bpf: Allow to change skb mark in test_run 2019-12-18 17:05:58 -08:00
bpfilter
bridge net: bridge: vlan: add per-vlan state 2020-01-24 12:58:14 +01:00
caif caif_usb: fix spelling mistake "to" -> "too" 2020-01-24 08:12:06 +01:00
can can: j1939: j1939_sk_bind(): take priv after lock is held 2019-12-08 11:52:02 +01:00
ceph libceph, rbd, ceph: convert to use the new mount API 2019-11-27 22:28:37 +01:00
core devlink: report 0 after hitting end in region read 2020-02-05 14:23:20 +01:00
dcb
dccp treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
decnet net: Make sock protocol value checks more specific 2020-01-09 18:41:40 -08:00
dns_resolver
dsa net: dsa: Fix use-after-free in probing of DSA switch tree 2020-01-27 11:12:46 +01:00
ethernet net: remove eth_change_mtu 2020-01-27 11:09:31 +01:00
ethtool net/core: Replace driver version to be kernel version 2020-01-27 13:47:22 +01:00
hsr net: hsr: fix possible NULL deref in hsr_handle_frame() 2020-02-04 09:27:07 +01:00
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
ife net: Fix Kconfig indentation 2019-09-26 08:56:17 +02:00
ipv4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-02-04 13:32:20 +00:00
ipv6 ipv6/addrconf: fix potential NULL deref in inet6_set_link_af() 2020-02-07 18:43:23 +01:00
iucv treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
kcm kcm: disable preemption in kcm_parse_func_strparser() 2019-09-27 10:27:14 +02:00
key
l2tp l2tp: Allow duplicate session creation with UDP 2020-02-04 12:35:49 +01:00
l3mdev
lapb
llc llc2: Fix return statement of llc_stat_ev_rx_null_dsap_xid_c (and _test_c) 2019-12-20 21:19:36 -08:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-01-28 16:02:33 -08:00
mac802154
mpls net: ipv6_stub: use ip6_dst_lookup_flow instead of ip6_dst_lookup 2019-12-04 12:27:13 -08:00
mptcp mptcp: fix use-after-free for ipv6 2020-02-06 11:25:09 +01:00
ncsi net/ncsi: Support for multi host mellanox card 2020-01-09 18:36:22 -08:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-02-04 13:32:20 +00:00
netlabel netlabel: remove redundant assignment to pointer iter 2019-09-01 11:45:02 -07:00
netlink treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
netrom net: core: add generic lockdep keys 2019-10-24 14:53:48 -07:00
nfc net: nfc: nci: fix a possible sleep-in-atomic-context bug in nci_uart_tty_receive() 2019-12-18 11:57:33 -08:00
nsh
openvswitch net: openvswitch: use skb_list_walk_safe helper for gso segments 2020-01-14 11:48:41 -08:00
packet y2038: core, driver and file system changes 2020-01-29 14:55:47 -08:00
phonet net: Remove redundant BUG_ON() check in phonet_pernet 2020-01-03 12:25:50 -08:00
psample net: psample: fix skb_over_panic 2019-11-26 14:40:13 -08:00
qrtr net: qrtr: Remove receive worker 2020-01-14 18:36:42 -08:00
rds net/rds: Use prefetch for On-Demand-Paging MR 2020-01-18 11:48:19 +02:00
rfkill rfkill: Fix incorrect check to avoid NULL pointer dereference 2019-12-16 10:15:49 +01:00
rose Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-26 10:40:21 +01:00
rxrpc rxrpc: Fix call RCU cleanup using non-bh-safe locks 2020-02-07 11:20:57 +01:00
sched taprio: Fix dropping packets when using taprio + ETF offloading 2020-02-07 11:30:03 +01:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-09 12:13:43 -08:00
smc net/smc: allow unprivileged users to read pnet table 2020-01-21 11:39:56 +01:00
strparser
sunrpc proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
switchdev
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-01-28 16:02:33 -08:00
tls Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2020-01-19 22:10:04 +01:00
unix skbuff: fix a data race in skb_queue_len() 2020-02-06 13:59:10 +01:00
vmw_vsock Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2020-01-19 22:10:04 +01:00
wimax
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-01-28 16:02:33 -08:00
x25 net/x25: fix nonblocking connect 2020-01-09 18:39:33 -08:00
xdp mm, tree-wide: rename put_user_page*() to unpin_user_page*() 2020-01-31 10:30:38 -08:00
xfrm treewide: remove redundant IS_ERR() before error code check 2020-02-04 03:05:27 +00:00
compat.c y2038: socket: use __kernel_old_timespec instead of timespec 2019-11-15 14:38:29 +01:00
Kconfig mptcp: Add MPTCP socket stubs 2020-01-24 13:44:07 +01:00
Makefile mptcp: Add MPTCP socket stubs 2020-01-24 13:44:07 +01:00
socket.c socket: fix unused-function warning 2020-01-08 15:02:21 -08:00
sysctl_net.c