On Wed, Dec 27, 2017 at 11:25:45PM +0100, Florian Westphal wrote: > 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: 880a6fab8f6ba5b ("xfrm: configure policy hash table thresholds by > netlink") > Fixes: 12a169e7d8f4b1c ("ipsec: Put dumpers on the dump list") > Cc: Herbert Xu <herb...@gondor.apana.org.au> > Cc: Timo Teras <timo.te...@iki.fi> > Cc: Christophe Gouault <christophe.goua...@6wind.com> > Reported-by: syzbot > <bot+c028095236fcb6f4348811565b75084c754dc...@syzkaller.appspotmail.com> > Signed-off-by: Florian Westphal <f...@strlen.de>
Applied, thanks a lot!