Messages in this thread Patch in this message | | | Date | Mon, 11 Feb 2008 19:27:35 +0100 | From | "Abel Bernabeu" <> | Subject | [Patch] Elf loader crash while zero-filling .bss |
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I've finally found a solution for the crash in load_binary_elf I reported last week:
http://lkml.org/lkml/2008/1/30/171
The attached patch solves my problem, but please test it yourself...
set_brk(start, end) allocs just page aligned regions (by "colapsing" both extremes to the start of the page in which they lay)... That means than even if both pointers are not equal there are still some chances that set_brk has allocated no space at all because ELF_PAGEALIGN(elf_bss) != ELF_PAGEALIGN(elf_brk).
So the condition was not correct.
--- linux-2.6.22.10.orig/fs/binfmt_elf.c 2008-02-11 18:58:29.000000000 +0100 +++ linux-2.6.22.10.hacked/fs/binfmt_elf.c 2008-02-11 16:09:41.000000000 +0100 @@ -939,3 +939,3 @@ static int load_elf_binary(struct linux_ } - if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { + if (likely(ELF_PAGEALIGN(elf_bss) != ELF_PAGEALIGN(elf_brk)) && unlikely(padzero(elf_bss))) { send_sig(SIGSEGV, current, 0);
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