Commit 5413b4c6c07b659e52c84a4e40d897b32b89834f

Authored by Allan Stephens
Committed by Paul Gortmaker
1 parent 3f8dd9446e

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>

Showing 2 changed files with 7 additions and 0 deletions Side-by-side Diff

include/linux/tipc_config.h
... ... @@ -193,6 +193,10 @@
193 193 #define TIPC_DEF_LINK_TOL 1500
194 194 #define TIPC_MAX_LINK_TOL 30000
195 195  
  196 +#if (TIPC_MIN_LINK_TOL < 16)
  197 +#error "TIPC_MIN_LINK_TOL is too small (abort limit may be NaN)"
  198 +#endif
  199 +
196 200 /*
197 201 * Link window limits (min, default, max), in packets
198 202 */
... ... @@ -2617,6 +2617,9 @@
2617 2617  
2618 2618 static void link_set_supervision_props(struct link *l_ptr, u32 tolerance)
2619 2619 {
  2620 + if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
  2621 + return;
  2622 +
2620 2623 l_ptr->tolerance = tolerance;
2621 2624 l_ptr->continuity_interval =
2622 2625 ((tolerance / 4) > 500) ? 500 : tolerance / 4;