forked from rpms/glibc
39 lines
1.4 KiB
Diff
39 lines
1.4 KiB
Diff
|
commit c0e82f117357a941e4d40fcc08babbd6a3c3a1b5
|
||
|
|
Author: Istvan Kurucsai <pistukem@gmail.com>
|
||
|
|
Date: Fri Dec 21 00:13:01 2018 -0500
|
||
|
|
|
||
|
|
malloc: Check the alignment of mmapped chunks before unmapping.
|
||
|
|
|
||
|
|
* malloc/malloc.c (munmap_chunk): Verify chunk alignment.
|
||
|
|
|
||
|
|
diff --git a/malloc/malloc.c b/malloc/malloc.c
|
||
|
|
index 4df5cb4862a7b854..4412a4ffc83b013b 100644
|
||
|
|
--- a/malloc/malloc.c
|
||
|
|
+++ b/malloc/malloc.c
|
||
|
|
@@ -2817,6 +2817,7 @@ systrim (size_t pad, mstate av)
|
||
|
|
static void
|
||
|
|
munmap_chunk (mchunkptr p)
|
||
|
|
{
|
||
|
|
+ size_t pagesize = GLRO (dl_pagesize);
|
||
|
|
INTERNAL_SIZE_T size = chunksize (p);
|
||
|
|
|
||
|
|
assert (chunk_is_mmapped (p));
|
||
|
|
@@ -2826,6 +2827,7 @@ munmap_chunk (mchunkptr p)
|
||
|
|
if (DUMPED_MAIN_ARENA_CHUNK (p))
|
||
|
|
return;
|
||
|
|
|
||
|
|
+ uintptr_t mem = (uintptr_t) chunk2mem (p);
|
||
|
|
uintptr_t block = (uintptr_t) p - prev_size (p);
|
||
|
|
size_t total_size = prev_size (p) + size;
|
||
|
|
/* Unfortunately we have to do the compilers job by hand here. Normally
|
||
|
|
@@ -2833,7 +2835,8 @@ munmap_chunk (mchunkptr p)
|
||
|
|
page size. But gcc does not recognize the optimization possibility
|
||
|
|
(in the moment at least) so we combine the two values into one before
|
||
|
|
the bit test. */
|
||
|
|
- if (__builtin_expect (((block | total_size) & (GLRO (dl_pagesize) - 1)) != 0, 0))
|
||
|
|
+ if (__glibc_unlikely ((block | total_size) & (pagesize - 1)) != 0
|
||
|
|
+ || __glibc_unlikely (!powerof2 (mem & (pagesize - 1))))
|
||
|
|
malloc_printerr ("munmap_chunk(): invalid pointer");
|
||
|
|
|
||
|
|
atomic_decrement (&mp_.n_mmaps);
|