linux-kernel - x86_64: potential critical issue with quicklists and page table pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20070921180742.GH20863@linux-os.sc.intel.com>
Date:	Fri, 21 Sep 2007 11:07:42 -0700
From:	"Siddha, Suresh B" <suresh.b.siddha@...el.com>
To:	torvalds@...ux-foundation.org, clameter@....com,
	akpm@...ux-foundation.org, ak@...e.de
Cc:	linux-kernel@...r.kernel.org, tony.luck@...el.com,
	asit.k.mallick@...el.com
Subject: x86_64: potential critical issue with quicklists and page table pages

git commit 34feb2c83beb3bdf13535a36770f7e50b47ef299 started using quicklists
for freeing page table pages and removed the usage of tlb_remove_page()

And looking at quicklist_free() and quicklist_free_page(), on a NUMA platform,
this can potentially free the page before the corresponding TLB caches
are flushed.

Essentially quicklist free routines are doing something like
__quicklist_free()
	...
	if (unlikely(nid != numa_node_id())) {
		__free_page(page);
		...
	}

	....


Now this will potentially cause a problem, if a cpu in someother node starts
using this page, while the corresponding TLB entries are still alive
in the original cpu which is still freeing the page table pages.

This violates the guideline documented in
http://developer.intel.com/design/processor/applnots/317080.pdf

This potentially can cause SW failures and hard to debug issues like
http://www.ussg.iu.edu/hypermail/linux/kernel/0205.2/1254.html

Can we revert this commit for 2.6.23 and look at this code post 2.6.23?

thanks,
suresh
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/