android_kernel_oneplus_msm8998/net/xfrm
Florian Westphal 10f64c9dfb xfrm: skip policies marked as dead while rehashing
commit 862591bf4f519d1b8d859af720fafeaebdd0162a upstream.

syzkaller triggered following KASAN splat:

BUG: KASAN: slab-out-of-bounds in xfrm_hash_rebuild+0xdbe/0xf00 net/xfrm/xfrm_policy.c:618
read of size 2 at addr ffff8801c8e92fe4 by task kworker/1:1/23 [..]
Workqueue: events xfrm_hash_rebuild [..]
 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428
 xfrm_hash_rebuild+0xdbe/0xf00 net/xfrm/xfrm_policy.c:618
 process_one_work+0xbbf/0x1b10 kernel/workqueue.c:2112
 worker_thread+0x223/0x1990 kernel/workqueue.c:2246 [..]

The reproducer triggers:
1016                 if (error) {
1017                         list_move_tail(&walk->walk.all, &x->all);
1018                         goto out;
1019                 }

in xfrm_policy_walk() via pfkey (it sets tiny rcv space, dump
callback returns -ENOBUFS).

In this case, *walk is located the pfkey socket struct, so this socket
becomes visible in the global policy list.

It looks like this is intentional -- phony walker has walk.dead set to 1
and all other places skip such "policies".

Ccing original authors of the two commits that seem to expose this
issue (first patch missed ->dead check, second patch adds pfkey
sockets to policies dumper list).

Fixes: 880a6fab8f ("xfrm: configure policy hash table thresholds by netlink")
Fixes: 12a169e7d8 ("ipsec: Put dumpers on the dump list")
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Timo Teras <timo.teras@iki.fi>
Cc: Christophe Gouault <christophe.gouault@6wind.com>
Reported-by: syzbot <bot+c028095236fcb6f4348811565b75084c754dc729@syzkaller.appspotmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-03 11:21:32 +02:00
..
Kconfig
Makefile
xfrm_algo.c ipsec: Replace seqniv with seqiv 2015-08-17 16:53:42 +08:00
xfrm_hash.c
xfrm_hash.h xfrm: hash prefixed policies based on preflen thresholds 2014-09-02 13:29:44 +02:00
xfrm_input.c xfrm: Fix crash observed during device unregistration and decryption 2016-04-20 15:42:05 +09:00
xfrm_ipcomp.c net: xfrm: use preempt-safe this_cpu_read() in ipcomp_alloc_tfms() 2018-04-08 11:51:59 +02:00
xfrm_output.c net: preserve IP control block during GSO segmentation 2016-01-31 11:29:00 -08:00
xfrm_policy.c xfrm: skip policies marked as dead while rehashing 2018-07-03 11:21:32 +02:00
xfrm_proc.c net: clean up snmp stats code 2014-05-07 16:06:05 -04:00
xfrm_replay.c xfrm: Always zero high-order sequence number bits 2015-05-21 06:56:23 +02:00
xfrm_state.c xfrm: fix xfrm_do_migrate() with AEAD e.g(AES-GCM) 2018-05-26 08:48:50 +02:00
xfrm_sysctl.c
xfrm_user.c xfrm_user: fix return value from xfrm_user_rcv_msg 2018-05-16 10:06:51 +02:00