[ipxe-devel] [PATCH] [cpio] Change truncated initramfs detection

Michael Brown mbrown at fensystems.co.uk
Tue Oct 30 02:35:45 UTC 2012

On Friday 26 Oct 2012 01:12:31 Shao Miller wrote:
> Subject: [PATCH] [cpio] Change truncated initramfs detection
> When Syslinux prepares an initramfs "initrd", the last file blob will
> not be padded to an initramfs alignment boundary.  We now determine
> that the initrd is truncated based on the unaligned length of the
> file data.

I think there's a corner case that could result in a crash: if cpio_len < len 
but cpio_align(cpio_len) > len, then len would underflow and bad things would 

Attached is a slightly modified patch which I think should still solve the 
problem, while guaranteeing that len cannot underflow.

Could you or Brandon test and let me know if this patch also works?


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