4.20-stable review patch. If anyone has any objections, please let me know.
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From: Pablo Neira Ayuso pablo@netfilter.org
commit 753c111f655e38bbd52fc01321266633f022ebe2 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/netfilter/nft_compat.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/netfilter/nft_compat.c +++ b/net/netfilter/nft_compat.c @@ -282,6 +282,7 @@ nft_target_destroy(const struct nft_ctx { 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; @@ -292,7 +293,7 @@ nft_target_destroy(const struct nft_ctx 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,