From 76a8ca39b3f95b898cd92546fb87ccaa2d1922c7 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Wed, 20 Jun 2018 09:22:47 +0200 Subject: [PATCH] hash: Fix potential null-pointer dereference in hash_expr_cmp() Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1504157 Upstream Status: nftables commit 5043a1e4847c0 commit 5043a1e4847c0149dabaf0b529a14a43b957e5e4 Author: Phil Sutter Date: Thu Mar 1 15:00:30 2018 +0100 hash: Fix potential null-pointer dereference in hash_expr_cmp() The first part of the conditional: | (e1->hash.expr || expr_cmp(e1->hash.expr, e2->hash.expr)) will call expr_cmp() in case e1->hash.expr is NULL, causing null-pointer dereference. This is probably a typo, the intention when introducing this was to avoid the call to expr_cmp() for symmetric hash expressions which don't use expr->hash.expr. Inverting the existence check should fix this. Fixes: 3a86406729782 ("src: hash: support of symmetric hash") Cc: Laura Garcia Liebana Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- src/hash.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/hash.c b/src/hash.c index 3355cad..e699963 100644 --- a/src/hash.c +++ b/src/hash.c @@ -36,7 +36,7 @@ static void hash_expr_print(const struct expr *expr, struct output_ctx *octx) static bool hash_expr_cmp(const struct expr *e1, const struct expr *e2) { - return (e1->hash.expr || + return (!e1->hash.expr || expr_cmp(e1->hash.expr, e2->hash.expr)) && e1->hash.mod == e2->hash.mod && e1->hash.seed_set == e2->hash.seed_set && -- 1.8.3.1