[3/3] netfilter: nft_compat: use-after-free when deleting targets
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Message ID 20190213174758.17275-4-pablo@netfilter.org
State Accepted
Delegated to: David Miller
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Series
  • [1/3] netfilter: compat: initialize all fields in xt_init
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Commit Message

Pablo Neira Ayuso Feb. 13, 2019, 5:47 p.m. UTC
Fetch pointer to module before target object is released.

Fixes: 29e3880109e3 ("netfilter: nf_tables: fix use-after-free when deleting compat expressions")
Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nft_compat.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch
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diff --git a/net/netfilter/nft_compat.c b/net/netfilter/nft_compat.c
index fe64df848365..0a4bad55a8aa 100644
--- a/net/netfilter/nft_compat.c
+++ b/net/netfilter/nft_compat.c
@@ -315,6 +315,7 @@  nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
 {
 	struct xt_target *target = expr->ops->data;
 	void *info = nft_expr_priv(expr);
+	struct module *me = target->me;
 	struct xt_tgdtor_param par;
 
 	par.net = ctx->net;
@@ -325,7 +326,7 @@  nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr)
 		par.target->destroy(&par);
 
 	if (nft_xt_put(container_of(expr->ops, struct nft_xt, ops)))
-		module_put(target->me);
+		module_put(me);
 }
 
 static int nft_extension_dump_info(struct sk_buff *skb, int attr,