From 9a19f26cd796c7321f659a8dbea5296b0eeea51d Mon Sep 17 00:00:00 2001 From: Noam Postavsky Date: Sat, 5 Nov 2016 16:51:53 -0400 Subject: [PATCH] Fix computation of regex stack limit The regex stack limit was being computed as the number of stack entries, whereas it was being compared with the current size as measured in bytes. This could cause indefinite looping when nearing the stack limit if re_max_failures happened not to be a multiple of sizeof fail_stack_elt_t (Bug #24751). * src/regex.c (GROW_FAIL_STACK): Compute both current stack size and limit as numbers of stack entries. --- src/regex.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/src/regex.c b/src/regex.c index 7e70c494f47..8aa54331fc7 100644 --- a/src/regex.c +++ b/src/regex.c @@ -1320,23 +1320,20 @@ typedef struct #define FAIL_STACK_GROWTH_FACTOR 4 #define GROW_FAIL_STACK(fail_stack) \ - (((fail_stack).size * sizeof (fail_stack_elt_t) \ - >= re_max_failures * TYPICAL_FAILURE_SIZE) \ + (((fail_stack).size >= re_max_failures * TYPICAL_FAILURE_SIZE) \ ? 0 \ : ((fail_stack).stack \ = REGEX_REALLOCATE_STACK ((fail_stack).stack, \ (fail_stack).size * sizeof (fail_stack_elt_t), \ - min (re_max_failures * TYPICAL_FAILURE_SIZE, \ - ((fail_stack).size * sizeof (fail_stack_elt_t) \ - * FAIL_STACK_GROWTH_FACTOR))), \ + min (re_max_failures * TYPICAL_FAILURE_SIZE, \ + ((fail_stack).size * FAIL_STACK_GROWTH_FACTOR)) \ + * sizeof (fail_stack_elt_t)), \ \ (fail_stack).stack == NULL \ ? 0 \ : ((fail_stack).size \ - = (min (re_max_failures * TYPICAL_FAILURE_SIZE, \ - ((fail_stack).size * sizeof (fail_stack_elt_t) \ - * FAIL_STACK_GROWTH_FACTOR)) \ - / sizeof (fail_stack_elt_t)), \ + = (min (re_max_failures * TYPICAL_FAILURE_SIZE, \ + ((fail_stack).size * FAIL_STACK_GROWTH_FACTOR))), \ 1))) -- 2.39.5