From: Richard Guenther <rguenther@suse.de>
To: David Sterba <dsterba@suse.cz>
Cc: Jan Kara <jack@suse.cz>, LKML <linux-kernel@vger.kernel.org>,
linux-ia64@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
ptesarik@suse.cz, gcc@gcc.gnu.org
Subject: Re: Memory corruption due to word sharing
Date: Thu, 2 Feb 2012 12:23:42 +0100 (CET) [thread overview]
Message-ID: <alpine.LNX.2.00.1202021222580.4999@zhemvz.fhfr.qr> (raw)
In-Reply-To: <20120202111340.GB28416@ds.suse.cz>
On Thu, 2 Feb 2012, David Sterba wrote:
> On Wed, Feb 01, 2012 at 04:19:18PM +0100, Jan Kara wrote:
> > We actually spotted this race in practice in btrfs on structure
> > fs/btrfs/ctree.h:struct btrfs_block_rsv where spinlock content got
> > corrupted due to update of following bitfield and there seem to be other
> > places in kernel where this could happen.
>
> Here's the list of structures where a bitfield is shared with spinlock
> or atomic/kref within an 8B word, generated from 3.3-rc2:
>
> spinlock+bitfield:
>
> Struct: struct ak4113; Field: init
> Struct: struct ak4114; Field: init
> Struct: struct ak4117; Field: init
> Struct: struct btrfs_block_rsv; Field: full
> Struct: struct cm109_dev; Field: buzzer_pending
> Struct: struct pch_udc_dev; Field: active
> Struct: struct rds_iw_device; Field: dma_local_lkey
> Struct: struct sierra_intf_private; Field: suspended
> Struct: struct sm501_gpio; Field: registered
> Struct: struct unix_sock; Field: gc_candidate
> Struct: struct usb_anchor; Field: poisoned
> Struct: struct usb_wwan_intf_private; Field: suspended
>
> atomic/kref+bitfield:
>
> Struct: struct dlm_lock_resource; Field: migration_pending
> Struct: struct extent_map; Field: in_tree
> Struct: struct kobject; Field: state_initialized
> Struct: struct page; Field: inuse
> Struct: struct rds_ib_connection; Field: i_flowctl
> Struct: struct rds_iw_connection; Field: i_flowctl
> Struct: struct sctp_transport; Field: dead
> Struct: struct transaction_s; Field: t_synchronous_commit
> Struct: struct xfs_ioend; Field: io_isasync
>
>
> Not all listed structs are necessarily subject to the bug. There may be
> another mechanism preventing concurrent access to the bitfield and
> spinlock/atomic, or the bitfield is modified from a single cpu, or is
> not used. But all of them need to be reviewed of course.
To hit this bug the containing objects also have to be at least
8-byte aligned.
Richard.
next prev parent reply other threads:[~2012-02-02 11:23 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-01 15:19 Memory corruption due to word sharing Jan Kara
2012-02-01 15:34 ` Markus Trippelsdorf
2012-02-01 16:37 ` Colin Walters
2012-02-01 16:56 ` Linus Torvalds
2012-02-01 17:11 ` Jiri Kosina
2012-02-01 17:37 ` Linus Torvalds
2012-02-01 17:41 ` Michael Matz
2012-02-01 18:09 ` David Miller
2012-02-01 18:45 ` Jeff Law
2012-02-01 19:09 ` Linus Torvalds
2012-02-02 15:51 ` Jeff Garzik
2012-02-01 18:57 ` Linus Torvalds
2012-02-01 19:04 ` Peter Bergner
2012-02-01 18:52 ` Linus Torvalds
2012-02-02 9:35 ` Richard Guenther
2012-02-02 9:37 ` Richard Guenther
2012-02-02 13:43 ` Michael Matz
2012-02-01 16:41 ` Linus Torvalds
2012-02-01 17:42 ` Torvald Riegel
2012-02-01 19:40 ` Jakub Jelinek
2012-02-01 20:01 ` Linus Torvalds
2012-02-01 20:16 ` Jakub Jelinek
2012-02-01 20:44 ` Linus Torvalds
2012-02-02 15:58 ` Aldy Hernandez
2012-02-02 16:28 ` Michael Matz
2012-02-02 17:51 ` Linus Torvalds
2012-02-01 20:19 ` Linus Torvalds
2012-02-02 9:46 ` Richard Guenther
2012-02-01 19:44 ` Boehm, Hans
2012-02-01 19:54 ` Jeff Law
2012-02-01 19:47 ` Linus Torvalds
2012-02-01 19:58 ` Alan Cox
2012-02-01 20:41 ` Torvald Riegel
2012-02-01 20:59 ` Linus Torvalds
2012-02-01 21:24 ` Torvald Riegel
2012-02-01 21:55 ` Linus Torvalds
2012-02-01 21:25 ` Boehm, Hans
2012-02-01 22:27 ` Linus Torvalds
2012-02-01 22:45 ` Paul E. McKenney
2012-02-01 23:11 ` Linus Torvalds
2012-02-02 18:42 ` Paul E. McKenney
2012-02-02 19:08 ` Linus Torvalds
2012-02-02 19:37 ` Paul E. McKenney
2012-02-03 16:38 ` Andrew MacLeod
2012-02-03 17:16 ` Linus Torvalds
2012-02-03 19:16 ` Andrew MacLeod
2012-02-03 20:00 ` Linus Torvalds
2012-02-03 20:19 ` Paul E. McKenney
2012-02-06 15:38 ` Torvald Riegel
2012-02-10 19:27 ` Richard Henderson
2012-02-02 11:19 ` Ingo Molnar
2012-02-01 21:04 ` Boehm, Hans
2012-02-02 9:28 ` Bernd Petrovitsch
2012-02-01 17:08 ` Torvald Riegel
2012-02-01 17:29 ` Linus Torvalds
2012-02-01 20:53 ` Torvald Riegel
2012-02-01 21:20 ` Linus Torvalds
2012-02-01 21:37 ` Torvald Riegel
2012-02-01 22:18 ` Boehm, Hans
2012-02-02 11:11 ` James Courtier-Dutton
2012-02-02 11:24 ` Richard Guenther
2012-02-02 11:13 ` David Sterba
2012-02-02 11:23 ` Richard Guenther [this message]
2012-02-03 6:45 ` DJ Delorie
2012-02-03 9:37 ` Richard Guenther
2012-02-03 10:03 ` Matthew Gretton-Dann
2012-02-01 17:52 Dennis Clarke
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