From 1159a193696ad48ec86e5895f6dee3e539619c0e Mon Sep 17 00:00:00 2001 From: Will Newton Date: Mon, 12 Aug 2013 15:08:02 +0100 Subject: [PATCH] malloc: Check for integer overflow in pvalloc. A large bytes parameter to pvalloc could cause an integer overflow and corrupt allocator internals. Check the overflow does not occur before continuing with the allocation. ChangeLog: 2013-09-11 Will Newton [BZ #15855] * malloc/malloc.c (__libc_pvalloc): Check the value of bytes does not overflow. --- ChangeLog | 6 ++++++ malloc/malloc.c | 7 +++++++ 2 files changed, 13 insertions(+) diff --git a/ChangeLog b/ChangeLog index 21ff1b8..b95693f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2013-09-11 Will Newton + + [BZ #15855] + * malloc/malloc.c (__libc_pvalloc): Check the value of bytes + does not overflow. + 2013-09-10 Ondřej Bílka * sysdeps/ieee754/dbl-64/e_j0.c: Remove DO_NOT_USE_THIS conditionals. diff --git a/malloc/malloc.c b/malloc/malloc.c index dd295f5..7f43ba3 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -3082,6 +3082,13 @@ __libc_pvalloc(size_t bytes) size_t page_mask = GLRO(dl_pagesize) - 1; size_t rounded_bytes = (bytes + page_mask) & ~(page_mask); + /* Check for overflow. */ + if (bytes > SIZE_MAX - 2*pagesz - MINSIZE) + { + __set_errno (ENOMEM); + return 0; + } + void *(*hook) (size_t, size_t, const void *) = force_reg (__memalign_hook); if (__builtin_expect (hook != NULL, 0)) -- 2.7.4