|From:||Linus Torvalds <torvalds-AT-linux-foundation.org>|
|To:||Vasiliy Kulikov <segoon-AT-openwall.com>|
|Subject:||Re: [RFC v1] implement SL*B and stack usercopy runtime checks|
|Date:||Sun, 3 Jul 2011 11:27:47 -0700|
|Cc:||kernel-hardening-AT-lists.openwall.com, Thomas Gleixner <tglx-AT-linutronix.de>, Ingo Molnar <mingo-AT-redhat.com>, "H. Peter Anvin" <hpa-AT-zytor.com>, x86-AT-kernel.org, Arnd Bergmann <arnd-AT-arndb.de>, Christoph Lameter <cl-AT-linux-foundation.org>, Pekka Enberg <penberg-AT-kernel.org>, Matt Mackall <mpm-AT-selenic.com>, Andrew Morton <akpm-AT-linux-foundation.org>, linux-kernel-AT-vger.kernel.org, linux-arch-AT-vger.kernel.org, linux-mm-AT-kvack.org|
That patch is entirely insane. No way in hell will that ever get merged. copy_to/from_user() is some of the most performance-critical code, and runs a *lot*, often for fairly small structures (ie 'fstat()' etc). Adding random ad-hoc tests to it is entirely inappropriate. Doing so unconditionally is insane. So NAK, NAK, NAK. If you seriously clean it up (that at a minimum includes things like making it configurable using some pretty helper function that just compiles away for all the normal cases, and not writing out if (!slab_access_ok(to, n) || !stack_access_ok(to, n)) multiple times, for chrissake) it _might_ be acceptable. But in its current form it's just total crap. It's exactly the kind of "crazy security people who don't care about anything BUT security" crap that I refuse to see. Some balance and sanity. Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to email@example.com. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"firstname.lastname@example.org"> email@example.com </a>
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