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From: Greg KH <gregkh@suse.de>
To: linux-kernel@vger.kernel.org, stable@kernel.org
Cc: stable-review@kernel.org, torvalds@linux-foundation.org,
	akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk,
	Sonny Rao <sonnyrao@us.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	anton@samba.org, rajamony@us.ibm.com, speight@us.ibm.com,
	mstephen@us.ibm.com, grimm@us.ibm.com, mikey@ozlabs.au.ibm.com,
	Ingo Molnar <mingo@elte.hu>
Subject: [patch 10/24] futexes: Fix infinite loop in get_futex_key() on huge page
Date: Fri, 17 Jul 2009 13:09:01 -0700	[thread overview]
Message-ID: <20090717201231.389120722@mini.kroah.org> (raw)
In-Reply-To: <20090717201639.GA14209@kroah.com>

[-- Attachment #1: futexes-fix-infinite-loop-in-get_futex_key-on-huge-page.patch --]
[-- Type: text/plain, Size: 1214 bytes --]

2.6.30-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Sonny Rao <sonnyrao@us.ibm.com>

commit ce2ae53b750abfaa012ce408e93da131a5b5649b upstream.

get_futex_key() can infinitely loop if it is called on a
virtual address that is within a huge page but not aligned to
the beginning of that page.  The call to get_user_pages_fast
will return the struct page for a sub-page within the huge page
and the check for page->mapping will always fail.

The fix is to call compound_head on the page before checking
that it's mapped.

Signed-off-by: Sonny Rao <sonnyrao@us.ibm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: anton@samba.org
Cc: rajamony@us.ibm.com
Cc: speight@us.ibm.com
Cc: mstephen@us.ibm.com
Cc: grimm@us.ibm.com
Cc: mikey@ozlabs.au.ibm.com
LKML-Reference: <20090710231313.GA23572@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 kernel/futex.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -241,6 +241,7 @@ again:
 	if (err < 0)
 		return err;
 
+	page = compound_head(page);
 	lock_page(page);
 	if (!page->mapping) {
 		unlock_page(page);



  parent reply	other threads:[~2009-07-17 20:22 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20090717200851.907421303@mini.kroah.org>
2009-07-17 20:16 ` [patch 00/24] 2.6.30.2-stable review Greg KH
2009-07-17 20:08   ` [patch 01/24] Add -fno-delete-null-pointer-checks to gcc CFLAGS Greg KH
2009-07-17 20:08   ` [patch 02/24] security: use mmap_min_addr indepedently of security models Greg KH
2009-07-17 20:08   ` [patch 03/24] tun/tap: Fix crashes if open() /dev/net/tun and then poll() it. (CVE-2009-1897) Greg KH
2009-07-17 20:08   ` [patch 04/24] personality: fix PER_CLEAR_ON_SETID (CVE-2009-1895) Greg KH
2009-07-17 20:08   ` [patch 05/24] Blackfin: fix accidental reset in some boot modes Greg KH
2009-07-17 20:08   ` [patch 06/24] Blackfin: redo handling of bad irqs Greg KH
2009-07-17 20:08   ` [patch 07/24] Blackfin: fix deadlock in SMP IPI handler Greg KH
2009-07-17 20:08   ` [patch 08/24] Blackfin: fix command line corruption with DEBUG_DOUBLEFAULT Greg KH
2009-07-17 20:09   ` [patch 09/24] futex: Fix the write access fault problem for real Greg KH
2009-07-17 20:09   ` Greg KH [this message]
2009-07-17 20:09   ` [patch 11/24] kernel/resource.c: fix sign extension in reserve_setup() Greg KH
2009-07-17 20:09   ` [patch 12/24] alpha: fix percpu build breakage Greg KH
2009-07-17 20:09   ` [patch 13/24] dma-debug: fix off-by-one error in overlap function Greg KH
2009-07-17 20:09   ` [patch 14/24] blocK: Restore barrier support for md and probably other virtual devices Greg KH
2009-07-17 20:09   ` [patch 15/24] md/raid5: suspend shouldnt affect read requests Greg KH
2009-07-17 20:09   ` [patch 16/24] md: fix error path when duplicate name is found on md device creation Greg KH
2009-07-17 20:09   ` [patch 17/24] md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes Greg KH
2009-07-17 20:09   ` [patch 18/24] Revert "ipv4: arp announce, arp_proxy and windows ip conflict verification" Greg KH
2009-07-17 20:09   ` [patch 19/24] floppy: fix lock imbalance Greg KH
2009-07-17 20:09   ` [patch 20/24] Fix pci_unmap_addr() et al on i386 Greg KH
2009-07-17 20:09   ` [patch 21/24] Fix iommu address space allocation Greg KH
2009-07-17 20:09   ` [patch 22/24] fuse: fix bad return value in fuse_file_poll() Greg KH
2009-07-17 20:09   ` [patch 23/24] fuse: fix return value of fuse_dev_write() Greg KH
2009-07-17 20:09   ` [patch 24/24] Dont use -fwrapv compiler option: its buggy in gcc-4.1.x Greg KH
2009-07-17 20:36   ` [patch 00/24] 2.6.30.2-stable review Greg KH

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