linux-kernel - [PATCH 4/10] I386 pgd clone under lock fix.patch

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <200704100006.l3A06Bao020614@zach-dev.vmware.com>
Date:	Mon, 9 Apr 2007 17:06:11 -0700
From:	Zachary Amsden <zach@...are.com>
To:	Andrew Morton <akpm@...l.org>, Andi Kleen <ak@....de>,
	Jeremy Fitzhardinge <jeremy@...p.org>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Chris Wright <chrisw@...s-sol.org>,
	Virtualization Mailing List <virtualization@...ts.osdl.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Zachary Amsden <zach@...are.com>
CC:	William Lee Irwin III <wli@...omorphy.com>
Subject: [PATCH 4/10] I386 pgd clone under lock fix.patch

Copying of the pgd range must happen under the pgd_lock.  This got broken by
the paravirt changes in the -mm tree.  Badness can result if you copy the pgd
before being added to the list when splitting or rejoining large pages.

Signed-off-by: Zachary Amsden <zach@...are.com>

diff -r 2247ff2c3fdb arch/i386/mm/pgtable.c
--- a/arch/i386/mm/pgtable.c	Thu Apr 05 17:29:15 2007 -0700
+++ b/arch/i386/mm/pgtable.c	Thu Apr 05 17:40:02 2007 -0700
@@ -241,18 +241,16 @@ void pgd_ctor(void *pgd, struct kmem_cac
 	/* !PAE, no pagetable sharing */
 	memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
 
+	spin_lock_irqsave(&pgd_lock, flags);
+
+	/* must happen under lock */
 	clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
 			swapper_pg_dir + USER_PTRS_PER_PGD,
 			KERNEL_PGD_PTRS);
-
-	spin_lock_irqsave(&pgd_lock, flags);
-
-	/* must happen under lock */
 	paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
 				__pa(swapper_pg_dir) >> PAGE_SHIFT,
 				USER_PTRS_PER_PGD,
 				KERNEL_PGD_PTRS);
-
 	pgd_list_add(pgd);
 	spin_unlock_irqrestore(&pgd_lock, flags);
 }
-
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/