[PATCH OLK-5.10 2/2] netfilter: complete validation of user input

From: Eric Dumazet edumazet@google.com

stable inclusion from stable-v5.10.216 commit cf4bc359b76144a3dd55d7c09464ef4c5f2b2b05 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9QG86 CVE: CVE-2024-35896

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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[ Upstream commit 65acf6e0501ac8880a4f73980d01b5d27648b956 ]

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 syzkaller@googlegroups.com Signed-off-by: Eric Dumazet edumazet@google.com Reviewed-by: Pablo Neira Ayuso pablo@netfilter.org Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Liu Jian liujian56@huawei.com --- 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(+)

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c index 48c6aa3d91ae..5823e89b8a73 100644 --- a/net/ipv4/netfilter/arp_tables.c +++ b/net/ipv4/netfilter/arp_tables.c @@ -965,6 +965,8 @@ 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;

@@ -1265,6 +1267,8 @@ 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 b46d58b9f3fe..22e9ff592cd7 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1119,6 +1119,8 @@ 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;

@@ -1505,6 +1507,8 @@ 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 d013395be05f..df7cd3d285e4 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1137,6 +1137,8 @@ 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;

@@ -1515,6 +1517,8 @@ 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;