linux/net/xfrm
Florian Westphal cb79a180f2 xfrm: defer daddr pointer assignment after spi parsing
syzbot reports:
BUG: KASAN: use-after-free in __xfrm_state_lookup+0x695/0x6b0
Read of size 4 at addr ffff8801d434e538 by task syzkaller647520/2991
[..]
__xfrm_state_lookup+0x695/0x6b0 net/xfrm/xfrm_state.c:833
xfrm_state_lookup+0x8a/0x160 net/xfrm/xfrm_state.c:1592
xfrm_input+0x8e5/0x22f0 net/xfrm/xfrm_input.c:302

The use-after-free is the ipv4 destination address, which points
to an skb head area that has been reallocated:
  pskb_expand_head+0x36b/0x1210 net/core/skbuff.c:1494
  __pskb_pull_tail+0x14a/0x17c0 net/core/skbuff.c:1877
  pskb_may_pull include/linux/skbuff.h:2102 [inline]
  xfrm_parse_spi+0x3d3/0x4d0 net/xfrm/xfrm_input.c:170
  xfrm_input+0xce2/0x22f0 net/xfrm/xfrm_input.c:291

so the real bug is that xfrm_parse_spi() uses pskb_may_pull, but
for now do smaller workaround that makes xfrm_input fetch daddr
after spi parsing.

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2017-11-02 11:53:53 +01:00
..
Kconfig Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2017-02-16 21:25:49 -05:00
Makefile xfrm: fix xfrm_dev_event() missing when compile without CONFIG_XFRM_OFFLOAD 2017-06-07 08:16:27 +02:00
xfrm_algo.c xfrm: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:11 -07:00
xfrm_device.c xfrm: Fix negative device refcount on offload failure. 2017-09-11 10:36:51 +02:00
xfrm_hash.c
xfrm_hash.h xfrm: use "unsigned int" in __xfrm6_pref_hash() 2017-03-24 07:03:12 +01:00
xfrm_input.c xfrm: defer daddr pointer assignment after spi parsing 2017-11-02 11:53:53 +01:00
xfrm_ipcomp.c
xfrm_output.c xfrm: Fix GSO for IPsec with GRE tunnel. 2017-10-31 09:20:35 +01:00
xfrm_policy.c xfrm: Fix xfrm_dst_cache memleak 2017-10-24 13:40:36 +02:00
xfrm_proc.c proc: Reduce cache miss in xfrm_statistics_seq_show 2016-09-30 01:50:45 -04:00
xfrm_replay.c xfrm: Add xfrm_replay_overflow functions for offloading 2017-04-14 10:07:01 +02:00
xfrm_state.c xfrm: Clear sk_dst_cache when applying per-socket policy. 2017-10-26 08:19:03 +02:00
xfrm_sysctl.c net: xfrm: Change u32 sysctl entries to use proc_douintvec 2016-09-07 23:17:53 -07:00
xfrm_user.c ipsec: Fix aborted xfrm policy dump crash 2017-10-23 09:35:48 +02:00