From 65acf6e0501ac8880a4f73980d01b5d27648b956 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 9 Apr 2024 12:07:41 +0000 Subject: netfilter: complete validation of user input In my recent commit, I missed that do_replace() handlers use copy_from_sockptr() (which I fixed), followed by unsafe copy_from_sockptr_offset() calls. In all functions, we can perform the @optlen validation before even calling xt_alloc_table_info() with the following check: if ((u64)optlen < (u64)tmp.size + sizeof(tmp)) return -EINVAL; Fixes: 0c83842df40f ("netfilter: validate user input for expected length") Reported-by: syzbot Signed-off-by: Eric Dumazet Reviewed-by: Pablo Neira Ayuso Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- net/ipv4/netfilter/arp_tables.c | 4 ++++ net/ipv4/netfilter/ip_tables.c | 4 ++++ net/ipv6/netfilter/ip6_tables.c | 4 ++++ 3 files changed, 12 insertions(+) (limited to 'net') diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index b150c9929b12e..14365b20f1c5c 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -966,6 +966,8 @@ static int do_replace(struct net *net, sockptr_t arg, unsigned int len) return -ENOMEM; if (tmp.num_counters == 0) return -EINVAL; + if ((u64)len < (u64)tmp.size + sizeof(tmp)) + return -EINVAL; tmp.name[sizeof(tmp.name)-1] = 0; @@ -1266,6 +1268,8 @@ static int compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) return -ENOMEM; if (tmp.num_counters == 0) return -EINVAL; + if ((u64)len < (u64)tmp.size + sizeof(tmp)) + return -EINVAL; tmp.name[sizeof(tmp.name)-1] = 0; diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index 4876707595781..fe89a056eb06c 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1118,6 +1118,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len) return -ENOMEM; if (tmp.num_counters == 0) return -EINVAL; + if ((u64)len < (u64)tmp.size + sizeof(tmp)) + return -EINVAL; tmp.name[sizeof(tmp.name)-1] = 0; @@ -1504,6 +1506,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) return -ENOMEM; if (tmp.num_counters == 0) return -EINVAL; + if ((u64)len < (u64)tmp.size + sizeof(tmp)) + return -EINVAL; tmp.name[sizeof(tmp.name)-1] = 0; diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 636b360311c53..131f7bb2110d3 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1135,6 +1135,8 @@ do_replace(struct net *net, sockptr_t arg, unsigned int len) return -ENOMEM; if (tmp.num_counters == 0) return -EINVAL; + if ((u64)len < (u64)tmp.size + sizeof(tmp)) + return -EINVAL; tmp.name[sizeof(tmp.name)-1] = 0; @@ -1513,6 +1515,8 @@ compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) return -ENOMEM; if (tmp.num_counters == 0) return -EINVAL; + if ((u64)len < (u64)tmp.size + sizeof(tmp)) + return -EINVAL; tmp.name[sizeof(tmp.name)-1] = 0; -- cgit 1.2.3-korg