ctcm: avoid wraparound in length of incoming data
Since the receive code should tolerate any incoming garbage, it
should be protected against a potential wraparound when manipulating
length values within incoming data.
block_len is unsigned, so a too large subtraction will cause a
wraparound.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c
index 59ce7fb..a7a2538 100644
--- a/drivers/s390/net/ctcm_main.c
+++ b/drivers/s390/net/ctcm_main.c
@@ -105,7 +105,8 @@
return;
}
pskb->protocol = ntohs(header->type);
- if (header->length <= LL_HEADER_LENGTH) {
+ if ((header->length <= LL_HEADER_LENGTH) ||
+ (len <= LL_HEADER_LENGTH)) {
if (!(ch->logflags & LOG_FLAG_ILLEGALSIZE)) {
CTCM_DBF_TEXT_(ERROR, CTC_DBF_ERROR,
"%s(%s): Illegal packet size %d(%d,%d)"