tipc: Improve handling of invalid link tolerance values
Enhances TIPC link code to ignore an invalid link tolerance value
contained in an incoming LINK_PROTOCOL message, rather than
processing the value and potentially causing a divide-by-zero error.
Also add a compile-time check that catches attempts to redefine
TIPC's minimum link tolerance value in a manner that might result
in the same divide-by-zero error at run-time.
Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/include/linux/tipc_config.h b/include/linux/tipc_config.h
index 7d42460a..c14102d 100644
--- a/include/linux/tipc_config.h
+++ b/include/linux/tipc_config.h
@@ -193,6 +193,10 @@
#define TIPC_DEF_LINK_TOL 1500
#define TIPC_MAX_LINK_TOL 30000
+#if (TIPC_MIN_LINK_TOL < 16)
+#error "TIPC_MIN_LINK_TOL is too small (abort limit may be NaN)"
+#endif
+
/*
* Link window limits (min, default, max), in packets
*/
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 1c5c53a..3c1c28c 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2617,6 +2617,9 @@
static void link_set_supervision_props(struct link *l_ptr, u32 tolerance)
{
+ if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
+ return;
+
l_ptr->tolerance = tolerance;
l_ptr->continuity_interval =
((tolerance / 4) > 500) ? 500 : tolerance / 4;