From 020f6cc5f75511c5974cfd454f224365bc0c2df4 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 3 Aug 2018 18:40:21 +0200 Subject: [PATCH] netfilter: conntrack: avoid use-after free on rmmod When the conntrack module is removed, we call nf_ct_iterate_destroy via nf_ct_l4proto_unregister(). Problem is that nf_conntrack_proto_fini() gets called after the conntrack hash table has already been freed. Just remove the l4proto unregister call, its unecessary as the nf_ct_protos[] array gets free'd right after anyway. v2: add comment wrt. missing unreg call. Fixes: a0ae2562c6c4b2 ("netfilter: conntrack: remove l3proto abstraction") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_proto.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c index 803607a90102..30070732ee50 100644 --- a/net/netfilter/nf_conntrack_proto.c +++ b/net/netfilter/nf_conntrack_proto.c @@ -940,14 +940,13 @@ void nf_conntrack_proto_fini(void) { unsigned int i; - nf_ct_l4proto_unregister(builtin_l4proto, - ARRAY_SIZE(builtin_l4proto)); nf_unregister_sockopt(&so_getorigdst); #if IS_ENABLED(CONFIG_IPV6) nf_unregister_sockopt(&so_getorigdst6); #endif - - /* free l3proto protocol tables */ + /* No need to call nf_ct_l4proto_unregister(), the register + * tables are free'd here anyway. + */ for (i = 0; i < ARRAY_SIZE(nf_ct_protos); i++) kfree(nf_ct_protos[i]); } -- GitLab