linux-kernel - Re: [PATCH v2 03/20] vmcore, sysfs: export ELF note segment size instead of vmcoreinfo data size

Open Source and information security mailing list archives

Date:	Tue, 05 Mar 2013 17:29:12 +0800
From:	Zhang Yanfei <zhangyanfei@...fujitsu.com>
To:	HATAYAMA Daisuke <d.hatayama@...fujitsu.com>
CC:	vgoyal@...hat.com, ebiederm@...ssion.com, cpw@....com,
	kumagai-atsushi@....nes.nec.co.jp, lisa.mitchell@...com,
	heiko.carstens@...ibm.com, akpm@...ux-foundation.org,
	kexec@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 03/20] vmcore, sysfs: export ELF note segment size
 instead of vmcoreinfo data size

于 2013年03月02日 16:36, HATAYAMA Daisuke 写道:
> p_memsz member of program header entry with PT_NOTE type needs to have
> size of the corresponding ELF note segment. Currently, vmcoreinfo
> exports data part only. If vmcoreinfo reachs vmcoreinfo_max_size, then
> in merge_note_headers_elf{32,64}, empty ELF note header cannot be
> found or buffer overrun can happen.
> 
> Note: kexec-tools assigns PAGE_SIZE to p_memsz for other ELF note
> types. Due to the above reason, the same issue occurs if actual ELF
> note data exceeds (PAGE_SIZE - 2 * KEXEC_NOTE_HEAD_BYTES).
> 
> Signed-off-by: HATAYAMA Daisuke <d.hatayama@...fujitsu.com>
> ---
> 
>  kernel/ksysfs.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
> index 6ada93c..97d2763 100644
> --- a/kernel/ksysfs.c
> +++ b/kernel/ksysfs.c
> @@ -126,7 +126,7 @@ static ssize_t vmcoreinfo_show(struct kobject *kobj,
>  {
>  	return sprintf(buf, "%lx %x\n",
>  		       paddr_vmcoreinfo_note(),
> -		       (unsigned int)vmcoreinfo_max_size);
> +		       (unsigned int)sizeof(vmcoreinfo_note));
>  }
>  KERNEL_ATTR_RO(vmcoreinfo);

Reviewed-by: Zhang Yanfei <zhangyanfei@...fujitsu.com>

>  
> 
> 
> _______________________________________________
> kexec mailing list
> kexec@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
> 

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