From cfde94be1d4286bc47633c6e6eaf4e659bd78066 Mon Sep 17 00:00:00 2001 From: Chris Liddell Date: Wed, 7 Jun 2017 14:55:12 +0100 Subject: [PATCH] Bug 697985: bounds check the array allocations methods The clump allocator has four allocation functions that use 'number of elements' and 'size of elements' parameters (rather than a simple 'number of bytes'). Those need specific bounds checking. --- base/gsalloc.c | 42 ++++++++++++++++++++++++++++-------------- 1 file changed, 28 insertions(+), 14 deletions(-) --- end of original header CVE: CVE-2017-9835 Upstream-Status: Backport [git://git.ghostscript.com/ghostpdl.git] Signed-off-by: Joe Slater diff --git a/base/gsalloc.c b/base/gsalloc.c index 741ba00..10c04dd 100644 --- a/base/gsalloc.c +++ b/base/gsalloc.c @@ -1248,19 +1248,32 @@ i_alloc_struct_immovable(gs_memory_t * mem, gs_memory_type_ptr_t pstype, alloc_trace("|+<.", imem, cname, pstype, size, obj); return obj; } + +static inline bool +alloc_array_check_size(ulong num_elements, ulong elt_size, ulong *lsize) +{ + int64_t s = (int64_t)num_elements * elt_size; + if (s > max_uint) { + return false; + } + *lsize = (ulong)s; + return true; +} + static byte * i_alloc_byte_array(gs_memory_t * mem, uint num_elements, uint elt_size, client_name_t cname) { gs_ref_memory_t * const imem = (gs_ref_memory_t *)mem; obj_header_t *obj; - + ulong lsize; #ifdef MEMENTO if (Memento_failThisEvent()) return NULL; #endif - - obj = alloc_obj(imem, (ulong) num_elements * elt_size, + if (alloc_array_check_size(num_elements, elt_size, &lsize) == false) + return NULL; + obj = alloc_obj(imem, lsize, &st_bytes, ALLOC_DIRECT, cname); if_debug6m('A', mem, "[a%d:+b.]%s -bytes-*(%lu=%u*%u) = 0x%lx\n", @@ -1275,13 +1288,14 @@ i_alloc_byte_array_immovable(gs_memory_t * mem, uint num_elements, { gs_ref_memory_t * const imem = (gs_ref_memory_t *)mem; obj_header_t *obj; - + ulong lsize; #ifdef MEMENTO if (Memento_failThisEvent()) return NULL; #endif - - obj = alloc_obj(imem, (ulong) num_elements * elt_size, + if (alloc_array_check_size(num_elements, elt_size, &lsize) == false) + return NULL; + obj = alloc_obj(imem, lsize, &st_bytes, ALLOC_IMMOVABLE | ALLOC_DIRECT, cname); @@ -1297,7 +1311,7 @@ i_alloc_struct_array(gs_memory_t * mem, uint num_elements, { gs_ref_memory_t * const imem = (gs_ref_memory_t *)mem; obj_header_t *obj; - + ulong lsize; #ifdef MEMENTO if (Memento_failThisEvent()) return NULL; @@ -1311,9 +1325,9 @@ i_alloc_struct_array(gs_memory_t * mem, uint num_elements, return NULL; /* fail */ } #endif - obj = alloc_obj(imem, - (ulong) num_elements * pstype->ssize, - pstype, ALLOC_DIRECT, cname); + if (alloc_array_check_size(num_elements, pstype->ssize, &lsize) == false) + return NULL; + obj = alloc_obj(imem, lsize, pstype, ALLOC_DIRECT, cname); if_debug7m('A', mem, "[a%d:+<.]%s %s*(%lu=%u*%u) = 0x%lx\n", alloc_trace_space(imem), client_name_string(cname), struct_type_name_string(pstype), @@ -1327,16 +1341,16 @@ i_alloc_struct_array_immovable(gs_memory_t * mem, uint num_elements, { gs_ref_memory_t * const imem = (gs_ref_memory_t *)mem; obj_header_t *obj; - + ulong lsize; #ifdef MEMENTO if (Memento_failThisEvent()) return NULL; #endif ALLOC_CHECK_SIZE(mem,pstype); - obj = alloc_obj(imem, - (ulong) num_elements * pstype->ssize, - pstype, ALLOC_IMMOVABLE | ALLOC_DIRECT, cname); + if (alloc_array_check_size(num_elements, pstype->ssize, &lsize) == false) + return NULL; + obj = alloc_obj(imem, lsize, pstype, ALLOC_IMMOVABLE | ALLOC_DIRECT, cname); if_debug7m('A', mem, "[a%d|+<.]%s %s*(%lu=%u*%u) = 0x%lx\n", alloc_trace_space(imem), client_name_string(cname), struct_type_name_string(pstype), -- 1.7.9.5