Hello Pablo Neira Ayuso,
The patch b8e204006340: "netfilter: nft_compat: use .release_ops and
remove list of extension" from Feb 13, 2019, leads to the following
static checker warning:
net/netfilter/nf_tables_api.c:2167 nf_tables_expr_destroy()
error: dereferencing freed memory 'expr->ops'
net/netfilter/nf_tables_api.c
2162 static void nf_tables_expr_destroy(const struct nft_ctx *ctx,
2163 struct nft_expr *expr)
2164 {
2165 if (expr->ops->destroy)
2166 expr->ops->destroy(ctx, expr);
^^^^
--> 2167 module_put(expr->ops->type->owner);
^^^^^^^^^
2168 }
Smatch says there are three functions which free expr->ops.
net/netfilter/nft_compat.c | nft_match_destroy | 121 | PARAM_FREED | 1 | $->ops |
net/netfilter/nft_compat.c | nft_match_large_destroy | 124 | PARAM_FREED | 1 | $->ops |
net/netfilter/nft_compat.c | nft_target_destroy | 56 | PARAM_FREED | 1 | $->ops |
regards,
dan carpenter
