From e2ae0d23953c4e04a38f9848eed84529a401b02e Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Sun, 20 Dec 2020 13:17:01 +0100 Subject: netfilter: ipset: fixes possible oops in mtype_resize 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 Signed-off-by: Jozsef Kadlecsik --- kernel/net/netfilter/ipset/ip_set_hash_gen.h | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) (limited to 'kernel/net/netfilter/ipset') diff --git a/kernel/net/netfilter/ipset/ip_set_hash_gen.h b/kernel/net/netfilter/ipset/ip_set_hash_gen.h index acfe0c8..4a4062e 100644 --- a/kernel/net/netfilter/ipset/ip_set_hash_gen.h +++ b/kernel/net/netfilter/ipset/ip_set_hash_gen.h @@ -149,6 +149,10 @@ htable_bits(u32 hashsize) /* Assume that hashsize == 2^htable_bits */ u8 bits = fls(hashsize - 1); + /* We must fit both into u32 in jhash and size_t */ + if (bits >= 31) + return 31; + if (jhash_size(bits) != hashsize) /* Round up to the first 2^n value */ bits = fls(hashsize); @@ -640,7 +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; @@ -664,14 +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; @@ -813,6 +815,12 @@ cleanup: 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 */ -- cgit v1.2.3