From f2e5ddcc0d12f9c4c7b254358ad245c9dddce13b Mon Sep 17 00:00:00 2001 From: Seif Mazareeb Date: Thu, 17 Oct 2013 20:33:21 -0700 Subject: [PATCH] net: fix cipso packet validation when !NETLABEL When CONFIG_NETLABEL is disabled, the cipso_v4_validate() function could loop forever in the main loop if opt[opt_iter +1] == 0, this will causing a kernel crash in an SMP system, since the CPU executing this function will stall /not respond to IPIs. This problem can be reproduced by running the IP Stack Integrity Checker (http://isic.sourceforge.net) using the following command on a Linux machine connected to DUT: "icmpsic -s rand -d -r 123456" wait (1-2 min) Signed-off-by: Seif Mazareeb Acked-by: Paul Moore Signed-off-by: David S. Miller --- include/net/cipso_ipv4.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h index a7a683e30b64..a8c2ef6d3b93 100644 --- a/include/net/cipso_ipv4.h +++ b/include/net/cipso_ipv4.h @@ -290,6 +290,7 @@ static inline int cipso_v4_validate(const struct sk_buff *skb, unsigned char err_offset = 0; u8 opt_len = opt[1]; u8 opt_iter; + u8 tag_len; if (opt_len < 8) { err_offset = 1; @@ -302,11 +303,12 @@ static inline int cipso_v4_validate(const struct sk_buff *skb, } for (opt_iter = 6; opt_iter < opt_len;) { - if (opt[opt_iter + 1] > (opt_len - opt_iter)) { + tag_len = opt[opt_iter + 1]; + if ((tag_len == 0) || (opt[opt_iter + 1] > (opt_len - opt_iter))) { err_offset = opt_iter + 1; goto out; } - opt_iter += opt[opt_iter + 1]; + opt_iter += tag_len; } out: -- 2.20.1