| From 45a0eaf77022963d639d6d19871dbab7b79703fc Mon Sep 17 00:00:00 2001 |
| From: Alan Modra <amodra@gmail.com> |
| Date: Tue, 23 Oct 2018 19:02:06 +1030 |
| Subject: [PATCH] PR23806, NULL pointer dereference in merge_strings |
| |
| PR 23806 |
| * merge.c (_bfd_add_merge_section): Don't attempt to merge |
| sections with ridiculously large alignments. |
| |
| Upstream-Status: Backport |
| CVE: CVE-2018-18606 |
| Signed-off-by: Zhixiong Chi <zhixiong.chi@windriver.com> |
| --- |
| bfd/ChangeLog | 6 ++++++ |
| bfd/merge.c | 15 +++++++++++---- |
| 2 files changed, 17 insertions(+), 4 deletions(-) |
| |
| --- a/bfd/merge.c |
| +++ b/bfd/merge.c |
| @@ -24,6 +24,7 @@ |
| as used in ELF SHF_MERGE. */ |
| |
| #include "sysdep.h" |
| +#include <limits.h> |
| #include "bfd.h" |
| #include "elf-bfd.h" |
| #include "libbfd.h" |
| @@ -385,12 +386,18 @@ _bfd_add_merge_section (bfd *abfd, void |
| return TRUE; |
| } |
| |
| - align = sec->alignment_power; |
| - if ((sec->entsize < (unsigned) 1 << align |
| +#ifndef CHAR_BIT |
| +#define CHAR_BIT 8 |
| +#endif |
| + if (sec->alignment_power >= sizeof (align) * CHAR_BIT) |
| + return TRUE; |
| + |
| + align = 1u << sec->alignment_power; |
| + if ((sec->entsize < align |
| && ((sec->entsize & (sec->entsize - 1)) |
| || !(sec->flags & SEC_STRINGS))) |
| - || (sec->entsize > (unsigned) 1 << align |
| - && (sec->entsize & (((unsigned) 1 << align) - 1)))) |
| + || (sec->entsize > align |
| + && (sec->entsize & (align - 1)))) |
| { |
| /* Sanity check. If string character size is smaller than |
| alignment, then we require character size to be a power |