Re: [patch 03/26] sysfs: zero terminate sysfs write buffers (CVE-2006-1055)

[Al Viro]

On Wed, Apr 05, 2006 at 07:09:28PM +0400, Sergey Vlasov wrote:
> This will break the "color_map" sysfs file for framebuffers -
> drivers/video/fbsysfs.c:store_cmap() expects to get exactly 4096 bytes
> for a colormap with 256 entries.  In fact, the original patch which
> changed PAGE_SIZE - 1 to PAGE_SIZE:

... cheerfully assuming that nobody assumes NUL-termination and
everyone (sysfs patch writers!) certainly uses the length argument.
Fscking brilliant, that.

Are you willing to audit all sysfs ->show() in the kernel?  Original
author of that turd had not been.

FWIW, "color_map" is a blatant abuse of interface.  Doesn't get
any more borderline...

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