From 2e3219b5c8a2e44e0b83ae6e04f52f20a82ac0f2 Mon Sep 17 00:00:00 2001
From: Wei Yongjun <yjwei@cn.fujitsu.com>
Date: Mon, 17 May 2010 22:51:58 -0700
Subject: [PATCH] sctp: fix append error cause to ERROR chunk correctly
commit 5fa782c2f5ef6c2e4f04d3e228412c9b4a4c8809
sctp: Fix skb_over_panic resulting from multiple invalid \
parameter errors (CVE-2010-1173) (v4)
cause 'error cause' never be add the the ERROR chunk due to
some typo when check valid length in sctp_init_cause_fixed().
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Reviewed-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/sctp/sm_make_chunk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index d8261f3d7715..bd2a50b482ac 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -141,7 +141,7 @@ int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
len = sizeof(sctp_errhdr_t) + paylen;
err.length = htons(len);
- if (skb_tailroom(chunk->skb) > len)
+ if (skb_tailroom(chunk->skb) < len)
return -ENOSPC;
chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
sizeof(sctp_errhdr_t),
@@ -1415,7 +1415,7 @@ void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
int len, const void *data)
{
- if (skb_tailroom(chunk->skb) > len)
+ if (skb_tailroom(chunk->skb) >= len)
return sctp_addto_chunk(chunk, len, data);
else
return NULL;
--
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