[SCTP]: Respect the real chunk length when walking parameters.

When performing bound checks during the parameter processing, we
want to use the real chunk and paramter lengths for bounds instead
of the rounded ones.  This prevents us from potentially walking of
the end if the chunk length was miscalculated.  We still use rounded
lengths when advancing the pointer. This was found during a
conformance test that changed the chunk length without modifying
parameters.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>

diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index e673b2c984e931c9a80d7c5e677bfdc1984fa4c3..aa6033ca7cd859d3614406a54b0d4885e79a94dc 100644 (file)
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -461,12 +461,12 @@ static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
  * there is room for a param header too.
  */
 #define sctp_walk_params(pos, chunk, member)\
-_sctp_walk_params((pos), (chunk), WORD_ROUND(ntohs((chunk)->chunk_hdr.length)), member)
+_sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 
 #define _sctp_walk_params(pos, chunk, end, member)\
 for (pos.v = chunk->member;\
      pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
-     pos.v <= (void *)chunk + end - WORD_ROUND(ntohs(pos.p->length)) &&\
+     pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
      pos.v += WORD_ROUND(ntohs(pos.p->length)))
 
@@ -477,7 +477,7 @@ _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
            sizeof(sctp_chunkhdr_t));\
      (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
-     (void *)err <= (void *)chunk_hdr + end - WORD_ROUND(ntohs(err->length)) &&\
+     (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))