From: Pablo Neira Ayuso pablo@netfilter.org
[ Upstream commit 3f3a390dbd59d236f62cff8e8b20355ef7069e3d ]
Smatch reports:
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.
Fixes: b8e204006340 ("netfilter: nft_compat: use .release_ops and remove list of extension") Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- net/netfilter/nf_tables_api.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index f272f9538c44..ef7ff13a7b99 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2113,9 +2113,11 @@ static int nf_tables_newexpr(const struct nft_ctx *ctx, static void nf_tables_expr_destroy(const struct nft_ctx *ctx, struct nft_expr *expr) { + const struct nft_expr_type *type = expr->ops->type; + if (expr->ops->destroy) expr->ops->destroy(ctx, expr); - module_put(expr->ops->type->owner); + module_put(type->owner); }
struct nft_expr *nft_expr_init(const struct nft_ctx *ctx,