From 161b838e25c6f83495e27e3f546b893622d442bf Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Mon, 14 Dec 2020 23:40:15 +0000 Subject: [PATCH 1/4] netfilter: nftables: fix incorrect increment of loop counter The intention of the err_expr cleanup path is to iterate over the allocated expr_array objects and free them, starting from i - 1 and working down to the start of the array. Currently the loop counter is being incremented instead of decremented and also the index i is being used instead of k, repeatedly destroying the same expr_array element. Fix this by decrementing k and using k as the index into expr_array. Addresses-Coverity: ("Infinite loop") Fixes: 8cfd9b0f8515 ("netfilter: nftables: generalize set expressions support") Signed-off-by: Colin Ian King Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 8d5aa0ac45f4..4186b1e52d58 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -5254,8 +5254,8 @@ static int nft_set_elem_expr_clone(const struct nft_ctx *ctx, return 0; err_expr: - for (k = i - 1; k >= 0; k++) - nft_expr_destroy(ctx, expr_array[i]); + for (k = i - 1; k >= 0; k--) + nft_expr_destroy(ctx, expr_array[k]); return -ENOMEM; } From 443d6e86f821a165fae3fc3fc13086d27ac140b1 Mon Sep 17 00:00:00 2001 From: Subash Abhinov Kasiviswanathan Date: Wed, 16 Dec 2020 21:38:02 -0700 Subject: [PATCH 2/4] netfilter: x_tables: Update remaining dereference to RCU This fixes the dereference to fetch the RCU pointer when holding the appropriate xtables lock. Reported-by: kernel test robot Fixes: cc00bcaa5899 ("netfilter: x_tables: Switch synchronization to RCU") Signed-off-by: Subash Abhinov Kasiviswanathan Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/arp_tables.c | 2 +- net/ipv4/netfilter/ip_tables.c | 2 +- net/ipv6/netfilter/ip6_tables.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 563b62b76a5f..c576a63d09db 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -1379,7 +1379,7 @@ static int compat_get_entries(struct net *net, xt_compat_lock(NFPROTO_ARP); t = xt_find_table_lock(net, NFPROTO_ARP, get.name); if (!IS_ERR(t)) { - const struct xt_table_info *private = t->private; + const struct xt_table_info *private = xt_table_get_private_protected(t); struct xt_table_info info; ret = compat_table_info(private, &info); diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 6e2851f8d3a3..e8f6f9d86237 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1589,7 +1589,7 @@ compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr, xt_compat_lock(AF_INET); t = xt_find_table_lock(net, AF_INET, get.name); if (!IS_ERR(t)) { - const struct xt_table_info *private = t->private; + const struct xt_table_info *private = xt_table_get_private_protected(t); struct xt_table_info info; ret = compat_table_info(private, &info); if (!ret && get.size == info.size) diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index c4f532f4d311..0d453fa9e327 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1598,7 +1598,7 @@ compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr, xt_compat_lock(AF_INET6); t = xt_find_table_lock(net, AF_INET6, get.name); if (!IS_ERR(t)) { - const struct xt_table_info *private = t->private; + const struct xt_table_info *private = xt_table_get_private_protected(t); struct xt_table_info info; ret = compat_table_info(private, &info); if (!ret && get.size == info.size) From 2b33d6ffa9e38f344418976b06057e2fc2aa9e2a Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Thu, 17 Dec 2020 11:53:40 +0300 Subject: [PATCH 3/4] 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 Acked-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- 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 5f1208ad049e..1e7dddf824ae 100644 --- a/net/netfilter/ipset/ip_set_hash_gen.h +++ b/net/netfilter/ipset/ip_set_hash_gen.h @@ -640,7 +640,7 @@ 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 +664,12 @@ 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 +811,12 @@ 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 */ From 5c8193f568ae16f3242abad6518dc2ca6c8eef86 Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Thu, 17 Dec 2020 17:53:18 +0300 Subject: [PATCH 4/4] netfilter: ipset: fix shift-out-of-bounds in htable_bits() htable_bits() can call jhash_size(32) and trigger shift-out-of-bounds UBSAN: shift-out-of-bounds in net/netfilter/ipset/ip_set_hash_gen.h:151:6 shift exponent 32 is too large for 32-bit type 'unsigned int' CPU: 0 PID: 8498 Comm: syz-executor519 Not tainted 5.10.0-rc7-next-20201208-syzkaller #0 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:395 htable_bits net/netfilter/ipset/ip_set_hash_gen.h:151 [inline] hash_mac_create.cold+0x58/0x9b net/netfilter/ipset/ip_set_hash_gen.h:1524 ip_set_create+0x610/0x1380 net/netfilter/ipset/ip_set_core.c:1115 nfnetlink_rcv_msg+0xecc/0x1180 net/netfilter/nfnetlink.c:252 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494 nfnetlink_rcv+0x1ac/0x420 net/netfilter/nfnetlink.c:600 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330 netlink_sendmsg+0x907/0xe40 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2345 ___sys_sendmsg+0xf3/0x170 net/socket.c:2399 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2432 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 This patch replaces htable_bits() by simple fls(hashsize - 1) call: it alone returns valid nbits both for round and non-round hashsizes. It is normal to set any nbits here because it is validated inside following htable_size() call which returns 0 for nbits>31. Fixes: 1feab10d7e6d("netfilter: ipset: Unified hash type generation") Reported-by: syzbot+d66bfadebca46cf61a2b@syzkaller.appspotmail.com Signed-off-by: Vasily Averin Acked-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_hash_gen.h | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h index 1e7dddf824ae..6186358eac7c 100644 --- a/net/netfilter/ipset/ip_set_hash_gen.h +++ b/net/netfilter/ipset/ip_set_hash_gen.h @@ -141,20 +141,6 @@ htable_size(u8 hbits) return hsize * sizeof(struct hbucket *) + sizeof(struct htable); } -/* Compute htable_bits from the user input parameter hashsize */ -static u8 -htable_bits(u32 hashsize) -{ - /* Assume that hashsize == 2^htable_bits */ - u8 bits = fls(hashsize - 1); - - if (jhash_size(bits) != hashsize) - /* Round up to the first 2^n value */ - bits = fls(hashsize); - - return bits; -} - #ifdef IP_SET_HASH_WITH_NETS #if IPSET_NET_COUNT > 1 #define __CIDR(cidr, i) (cidr[i]) @@ -1525,7 +1511,11 @@ IPSET_TOKEN(HTYPE, _create)(struct net *net, struct ip_set *set, if (!h) return -ENOMEM; - hbits = htable_bits(hashsize); + /* Compute htable_bits from the user input parameter hashsize. + * Assume that hashsize == 2^htable_bits, + * otherwise round up to the first 2^n value. + */ + hbits = fls(hashsize - 1); hsize = htable_size(hbits); if (hsize == 0) { kfree(h);