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netfilter: conntrack: avoid use-after free on rmmod

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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: a0ae2562c6 ("netfilter: conntrack: remove l3proto abstraction")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2018-08-03 18:40:21 +02:00 committed by Pablo Neira Ayuso
parent 7bdfcea875
commit 020f6cc5f7
1 changed files with 3 additions and 4 deletions
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7
net/netfilter/nf_conntrack_proto.c
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@ -940,14 +940,13 @@ void nf_conntrack_proto_fini(void)
{ {
unsigned int i; unsigned int i;
nf_ct_l4proto_unregister(builtin_l4proto,
ARRAY_SIZE(builtin_l4proto));
nf_unregister_sockopt(&so_getorigdst); nf_unregister_sockopt(&so_getorigdst);
#if IS_ENABLED(CONFIG_IPV6) #if IS_ENABLED(CONFIG_IPV6)
nf_unregister_sockopt(&so_getorigdst6); nf_unregister_sockopt(&so_getorigdst6);
#endif #endif
/* No need to call nf_ct_l4proto_unregister(), the register
/* free l3proto protocol tables */ * tables are free'd here anyway.
*/
for (i = 0; i < ARRAY_SIZE(nf_ct_protos); i++) for (i = 0; i < ARRAY_SIZE(nf_ct_protos); i++)
kfree(nf_ct_protos[i]); kfree(nf_ct_protos[i]);
} }