[23/23] sctp: fix append error cause to ERROR chunk correctly

Greg KH
2010-07-01T18:11:40Z

2.6.27-stable review patch. If anyone has any objections, please let us know.

------------------

From: Wei Yongjun <yjwei@cn.fujitsu.com>

commit 2e3219b5c8a2e44e0b83ae6e04f52f20a82ac0f2 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
net/sctp/sm_make_chunk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -140,7 +140,7 @@ int sctp_init_cause_fixed(struct sctp_ch
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),
@@ -1401,7 +1401,7 @@ void *sctp_addto_chunk(struct sctp_chunk
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;