[PATCH AUTOSEL 5.4 05/28] netfilter: ipset: fixes possible oops in mtype_resize
From: Sasha Levin <sashal@kernel.org>
Date: 2021-01-12 13:13:38
Also in:
lkml, netdev, netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Vasily Averin <redacted>
[ Upstream commit 2b33d6ffa9e38f344418976b06057e2fc2aa9e2a ]
currently mtype_resize() can cause oops
t = ip_set_alloc(htable_size(htable_bits));
if (!t) {
ret = -ENOMEM;
goto out;
}
t->hregion = ip_set_alloc(ahash_sizeof_regions(htable_bits));
Increased htable_bits can force htable_size() to return 0.
In own turn ip_set_alloc(0) returns not 0 but ZERO_SIZE_PTR,
so follwoing access to t->hregion should trigger an OOPS.
Signed-off-by: Vasily Averin <redacted>
Acked-by: Jozsef Kadlecsik <redacted>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/ipset/ip_set_hash_gen.h | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h
index a7a982a3e6761..8e9f6e1819014 100644
--- a/net/netfilter/ipset/ip_set_hash_gen.h
+++ b/net/netfilter/ipset/ip_set_hash_gen.h@@ -644,7 +644,7 @@ mtype_resize(struct ip_set *set, bool retried) struct htype *h = set->data; struct htable *t, *orig; u8 htable_bits; - size_t dsize = set->dsize; + size_t hsize, dsize = set->dsize; #ifdef IP_SET_HASH_WITH_NETS u8 flags; struct mtype_elem *tmp;
@@ -668,14 +668,12 @@ mtype_resize(struct ip_set *set, bool retried) retry: ret = 0; htable_bits++; - if (!htable_bits) { - /* In case we have plenty of memory :-) */ - pr_warn("Cannot increase the hashsize of set %s further\n", - set->name); - ret = -IPSET_ERR_HASH_FULL; - goto out; - } - t = ip_set_alloc(htable_size(htable_bits)); + if (!htable_bits) + goto hbwarn; + hsize = htable_size(htable_bits); + if (!hsize) + goto hbwarn; + t = ip_set_alloc(hsize); if (!t) { ret = -ENOMEM; goto out;
@@ -817,6 +815,12 @@ mtype_resize(struct ip_set *set, bool retried) if (ret == -EAGAIN) goto retry; goto out; + +hbwarn: + /* In case we have plenty of memory :-) */ + pr_warn("Cannot increase the hashsize of set %s further\n", set->name); + ret = -IPSET_ERR_HASH_FULL; + goto out; } /* Get the current number of elements and ext_size in the set */
--
2.27.0