From: Alan Modra <amodra@sourceware.org>
To: bfd-cvs@sourceware.org
Subject: [binutils-gdb] Re: bfd_elf_set_group_contents assertion
Date: Tue, 23 Aug 2022 09:05:06 +0000 (GMT) [thread overview]
Message-ID: <20220823090506.CE7DE3858C50@sourceware.org> (raw)
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6ecc36f7b7a29952579a49dc3d90f6871c6ab238
commit 6ecc36f7b7a29952579a49dc3d90f6871c6ab238
Author: Alan Modra <amodra@gmail.com>
Date: Tue Aug 23 18:24:36 2022 +0930
Re: bfd_elf_set_group_contents assertion
Further to commit 7744e3278b9f.
* elf.c (bfd_elf_set_group_contents): Restrict loc in loop writing
contents, and add another assertion.
Diff:
---
bfd/elf.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/bfd/elf.c b/bfd/elf.c
index 35aa45e3b90..f186a2cffe9 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -3594,6 +3594,8 @@ bfd_elf_set_group_contents (bfd *abfd, asection *sec, void *failedptrarg)
{
elf_sec->rel.hdr->sh_flags |= SHF_GROUP;
loc -= 4;
+ if (loc == sec->contents)
+ break;
H_PUT_32 (abfd, elf_sec->rel.idx, loc);
}
if (elf_sec->rela.hdr != NULL
@@ -3603,9 +3605,13 @@ bfd_elf_set_group_contents (bfd *abfd, asection *sec, void *failedptrarg)
{
elf_sec->rela.hdr->sh_flags |= SHF_GROUP;
loc -= 4;
+ if (loc == sec->contents)
+ break;
H_PUT_32 (abfd, elf_sec->rela.idx, loc);
}
loc -= 4;
+ if (loc == sec->contents)
+ break;
H_PUT_32 (abfd, elf_sec->this_idx, loc);
}
elt = elf_next_in_group (elt);
@@ -3613,12 +3619,20 @@ bfd_elf_set_group_contents (bfd *abfd, asection *sec, void *failedptrarg)
break;
}
- loc -= 4;
- if (loc != sec->contents)
+ /* We should always get here with loc == sec->contents + 4, but it is
+ possible to craft bogus SHT_GROUP sections that will cause segfaults
+ in objcopy without checking loc here and in the loop above. */
+ if (loc == sec->contents)
+ BFD_ASSERT (0);
+ else
{
- BFD_ASSERT (0);
- memset (sec->contents + 4, 0, loc - sec->contents);
- loc = sec->contents;
+ loc -= 4;
+ if (loc != sec->contents)
+ {
+ BFD_ASSERT (0);
+ memset (sec->contents + 4, 0, loc - sec->contents);
+ loc = sec->contents;
+ }
}
H_PUT_32 (abfd, sec->flags & SEC_LINK_ONCE ? GRP_COMDAT : 0, loc);
reply other threads:[~2022-08-23 9:05 UTC|newest]
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