diff options
| author | Leonardo Bras <leonardo@linux.ibm.com> | 2019-08-30 15:13:53 -0300 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-09-03 22:53:56 +0200 |
| commit | 88209141392a4a2521a2f67c13d7db5e84efbb58 (patch) | |
| tree | 05f1ede317f6cadcbed2d1f6cdad0a8111384ba1 | |
| parent | 039b1f4f24ecc8493b6bb9d70b4b78750d1b35c2 (diff) | |
netfilter: nft_fib_netdev: Terminate rule eval if protocol=IPv6 and ipv6 module is disabled
If IPv6 is disabled on boot (ipv6.disable=1), but nft_fib_inet ends up
dealing with a IPv6 packet, it causes a kernel panic in
fib6_node_lookup_1(), crashing in bad_page_fault.
The panic is caused by trying to deference a very low address (0x38
in ppc64le), due to ipv6.fib6_main_tbl = NULL.
BUG: Kernel NULL pointer dereference at 0x00000038
The kernel panic was reproduced in a host that disabled IPv6 on boot and
have to process guest packets (coming from a bridge) using it's ip6tables.
Terminate rule evaluation when packet protocol is IPv6 but the ipv6 module
is not loaded.
Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | net/netfilter/nft_fib_netdev.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/netfilter/nft_fib_netdev.c b/net/netfilter/nft_fib_netdev.c index 2cf3f32fe6d2..a2e726ae7f07 100644 --- a/net/netfilter/nft_fib_netdev.c +++ b/net/netfilter/nft_fib_netdev.c @@ -14,6 +14,7 @@ #include <linux/netfilter/nf_tables.h> #include <net/netfilter/nf_tables_core.h> #include <net/netfilter/nf_tables.h> +#include <net/ipv6.h> #include <net/netfilter/nft_fib.h> @@ -34,6 +35,8 @@ static void nft_fib_netdev_eval(const struct nft_expr *expr, } break; case ETH_P_IPV6: + if (!ipv6_mod_enabled()) + break; switch (priv->result) { case NFT_FIB_RESULT_OIF: case NFT_FIB_RESULT_OIFNAME: |