netfilter: complete validation of user input
authorEric Dumazet <edumazet@google.com>
Tue, 9 Apr 2024 12:07:41 +0000 (12:07 +0000)
committerJakub Kicinski <kuba@kernel.org>
Thu, 11 Apr 2024 02:42:56 +0000 (19:42 -0700)
commit65acf6e0501ac8880a4f73980d01b5d27648b956
tree025f335247a2f542a64459c92bea52025ecfb496
parent97e176fcbbf3c0f2bd410c9b241177c051f57176
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 <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>
net/ipv4/netfilter/arp_tables.c
net/ipv4/netfilter/ip_tables.c
net/ipv6/netfilter/ip6_tables.c