From dc165f7b0bfa73ebd64584331d0cb7c2ead66147 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Fri, 10 Dec 2004 01:36:18 +0000 Subject: Update. 2004-12-09 Ulrich Drepper * malloc/malloc.c (public_rEALLOc): Add parameter checks. (_int_free): Provide better error message for invalid pointers. --- malloc/malloc.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) (limited to 'malloc') diff --git a/malloc/malloc.c b/malloc/malloc.c index b62ffb57c0..cf1b935ffd 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -3434,6 +3434,17 @@ public_rEALLOc(Void_t* oldmem, size_t bytes) oldp = mem2chunk(oldmem); oldsize = chunksize(oldp); + /* Little security check which won't hurt performance: the + allocator never wrapps around at the end of the address space. + Therefore we can exclude some size values which might appear + here by accident or by "design" from some intruder. */ + if (__builtin_expect ((uintptr_t) oldp > (uintptr_t) -oldsize, 0) + || __builtin_expect ((uintptr_t) oldp & MALLOC_ALIGN_MASK, 0)) + { + malloc_printerr (check_action, "realloc(): invalid pointer", oldmem); + return NULL; + } + checked_request2size(bytes, nb); #if HAVE_MMAP @@ -4205,7 +4216,6 @@ _int_free(mstate av, Void_t* mem) mchunkptr bck; /* misc temp for linking */ mchunkptr fwd; /* misc temp for linking */ - const char *errstr = NULL; p = mem2chunk(mem); @@ -4215,7 +4225,8 @@ _int_free(mstate av, Void_t* mem) allocator never wrapps around at the end of the address space. Therefore we can exclude some size values which might appear here by accident or by "design" from some intruder. */ - if (__builtin_expect ((uintptr_t) p > (uintptr_t) -size, 0)) + if (__builtin_expect ((uintptr_t) p > (uintptr_t) -size, 0) + || __builtin_expect ((uintptr_t) p & MALLOC_ALIGN_MASK, 0)) { errstr = "free(): invalid pointer"; errout: -- cgit v1.2.3