From: Florian Westphal Date: Tue, 13 Dec 2016 12:59:33 +0000 (+0100) Subject: netfilter: nf_tables: fix oob access X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3e38df136e453aa69eb4472108ebce2fb00b1ba6;p=linux-beck.git netfilter: nf_tables: fix oob access BUG: KASAN: slab-out-of-bounds in nf_tables_rule_destroy+0xf1/0x130 at addr ffff88006a4c35c8 Read of size 8 by task nft/1607 When we've destroyed last valid expr, nft_expr_next() returns an invalid expr. We must not dereference it unless it passes != nft_expr_last() check. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index a019a87e58ee..0db5f9782265 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2115,7 +2115,7 @@ static void nf_tables_rule_destroy(const struct nft_ctx *ctx, * is called on error from nf_tables_newrule(). */ expr = nft_expr_first(rule); - while (expr->ops && expr != nft_expr_last(rule)) { + while (expr != nft_expr_last(rule) && expr->ops) { nf_tables_expr_destroy(ctx, expr); expr = nft_expr_next(expr); }