From 1c938663d58b5b2965976a6f54cc51b5d6f691aa Mon Sep 17 00:00:00 2001 From: Krzysztof Halasa Date: Fri, 11 Jun 2010 01:08:20 +0200 Subject: [PATCH] kbuild: Fix modpost segfault MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Alan writes: > program: /home/alan/GitTrees/linux-2.6-mid-ref/scripts/mod/modpost -o > Module.symvers -S vmlinux.o > > Program received signal SIGSEGV, Segmentation fault. It just hit me. It's the offset calculation in reloc_location() which overflows: return (void *)elf->hdr + sechdrs[section].sh_offset + (r->r_offset - sechdrs[section].sh_addr); E.g. for the first rodata r entry: r->r_offset < sechdrs[section].sh_addr and the expression in the parenthesis produces 0xFFFFFFE0 or something equally wise. Reported-by: Alan Signed-off-by: Krzysztof Hałasa Tested-by: Alan Signed-off-by: Michal Marek --- scripts/mod/modpost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 3318692e4e76..f8779006986d 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1342,7 +1342,7 @@ static unsigned int *reloc_location(struct elf_info *elf, int section = sechdr->sh_info; return (void *)elf->hdr + sechdrs[section].sh_offset + - (r->r_offset - sechdrs[section].sh_addr); + r->r_offset - sechdrs[section].sh_addr; } static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)