From a17777d161583401983a6dc1e5a659c9dc2f5257 Mon Sep 17 00:00:00 2001 From: Alex Budovski Date: Fri, 7 Jan 2011 11:35:43 +1100 Subject: [PATCH] Fixed two buffer handling errors in vector.c - remove() would read one-past array bounds. - resize() would fail if the initial size was 1, because it multiplied by 1.75 and truncated the resulting value. The buffer would always remain at size 1, but elements would repeatedly be appended (via insert()) causing a crash. --- src/vector.c | 4 ++-- tests/t0004-vector.c | 27 +++++++++++++++++++++++++++ 2 files changed, 29 insertions(+), 2 deletions(-) create mode 100644 tests/t0004-vector.c diff --git a/src/vector.c b/src/vector.c index 47e8ce845..325f34306 100644 --- a/src/vector.c +++ b/src/vector.c @@ -34,7 +34,7 @@ static int resize_vector(git_vector *v) { void **new_contents; - v->_alloc_size = (unsigned int)(v->_alloc_size * resize_factor); + v->_alloc_size = ((unsigned int)(v->_alloc_size * resize_factor)) + 1; if (v->_alloc_size == 0) v->_alloc_size = minimum_size; @@ -130,7 +130,7 @@ int git_vector_remove(git_vector *v, unsigned int idx) if (idx >= v->length || v->length == 0) return GIT_ENOTFOUND; - for (i = idx; i < v->length; ++i) + for (i = idx; i < v->length - 1; ++i) v->contents[i] = v->contents[i + 1]; v->length--; diff --git a/tests/t0004-vector.c b/tests/t0004-vector.c new file mode 100644 index 000000000..bee71d2f2 --- /dev/null +++ b/tests/t0004-vector.c @@ -0,0 +1,27 @@ +#include "test_lib.h" +#include "common.h" +#include "vector.h" + +/* Initial size of 1 will cause writing past array bounds prior to fix */ +BEGIN_TEST(initial_size_one) + git_vector x; + int i; + git_vector_init(&x, 1, NULL, NULL); + for (i = 0; i < 10; ++i) { + git_vector_insert(&x, (void*) 0xabc); + } + git_vector_free(&x); +END_TEST + +/* vector used to read past array bounds on remove() */ +BEGIN_TEST(remove) + git_vector x; + // make initial capacity exact for our insertions. + git_vector_init(&x, 3, NULL, NULL); + git_vector_insert(&x, (void*) 0xabc); + git_vector_insert(&x, (void*) 0xdef); + git_vector_insert(&x, (void*) 0x123); + + git_vector_remove(&x, 0); // used to read past array bounds. + git_vector_free(&x); +END_TEST