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From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 3/6] netfilter: nf_tables: fix oob access
Date: Thu,  5 Jan 2017 12:19:50 +0100	[thread overview]
Message-ID: <1483615193-2931-4-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1483615193-2931-1-git-send-email-pablo@netfilter.org>

From: Florian Westphal <fw@strlen.de>

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 <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_tables_api.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

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);
 	}
-- 
2.1.4

  parent reply	other threads:[~2017-01-05 11:19 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-05 11:19 [PATCH 0/6] Netfilter fixes for net Pablo Neira Ayuso
2017-01-05 11:19 ` [PATCH 1/6] netfilter: nft_quota: reset quota after dump Pablo Neira Ayuso
2017-01-05 11:19 ` [PATCH 2/6] netfilter: nft_queue: use raw_smp_processor_id() Pablo Neira Ayuso
2017-01-05 11:19 ` Pablo Neira Ayuso [this message]
2017-01-05 11:19 ` [PATCH 4/6] netfilter: nft_payload: mangle ckecksum if NFT_PAYLOAD_L4CSUM_PSEUDOHDR is set Pablo Neira Ayuso
2017-01-05 11:19 ` [PATCH 5/6] netfilter: ipt_CLUSTERIP: check duplicate config when initializing Pablo Neira Ayuso
2017-01-05 11:19 ` [PATCH 6/6] bridge: netfilter: Fix dropping packets that moving through bridge interface Pablo Neira Ayuso
2017-01-05 16:52 ` [PATCH 0/6] Netfilter fixes for net David Miller

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