sctp: fix append error cause to ERROR chunk correctly

commit 5fa782c2f5
  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>
This commit is contained in:
Wei Yongjun 2010-05-17 22:51:58 -07:00 committed by David S. Miller
parent f8bd909183
commit 2e3219b5c8

View file

@ -141,7 +141,7 @@ int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
len = sizeof(sctp_errhdr_t) + paylen; len = sizeof(sctp_errhdr_t) + paylen;
err.length = htons(len); err.length = htons(len);
if (skb_tailroom(chunk->skb) > len) if (skb_tailroom(chunk->skb) < len)
return -ENOSPC; return -ENOSPC;
chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
sizeof(sctp_errhdr_t), 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, void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
int len, const void *data) int len, const void *data)
{ {
if (skb_tailroom(chunk->skb) > len) if (skb_tailroom(chunk->skb) >= len)
return sctp_addto_chunk(chunk, len, data); return sctp_addto_chunk(chunk, len, data);
else else
return NULL; return NULL;