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From: Greg KH <gregkh@suse.de>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org,
	alan@lxorguk.ukuu.org.uk,
	Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Subject: [06/27] UBI: fix use-after-free on error path
Date: Mon, 23 Jan 2012 15:40:52 -0800	[thread overview]
Message-ID: <20120123234202.200082801@clark.kroah.org> (raw)
In-Reply-To: <20120123234224.GA19510@kroah.com>

2.6.32-longterm review patch.  If anyone has any objections, please let me know.

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

From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

commit e57e0d8e818512047fe379157c3f77f1b9fabffb upstream.

When we fail to erase a PEB, we free the corresponding erase entry object,
but then re-schedule this object if the error code was something like -EAGAIN.
Obviously, it is a bug to use the object after we have freed it.

Reported-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/mtd/ubi/wl.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/drivers/mtd/ubi/wl.c
+++ b/drivers/mtd/ubi/wl.c
@@ -1036,7 +1036,6 @@ static int erase_worker(struct ubi_devic
 
 	ubi_err("failed to erase PEB %d, error %d", pnum, err);
 	kfree(wl_wrk);
-	kmem_cache_free(ubi_wl_entry_slab, e);
 
 	if (err == -EINTR || err == -ENOMEM || err == -EAGAIN ||
 	    err == -EBUSY) {
@@ -1049,14 +1048,16 @@ static int erase_worker(struct ubi_devic
 			goto out_ro;
 		}
 		return err;
-	} else if (err != -EIO) {
+	}
+
+	kmem_cache_free(ubi_wl_entry_slab, e);
+	if (err != -EIO)
 		/*
 		 * If this is not %-EIO, we have no idea what to do. Scheduling
 		 * this physical eraseblock for erasure again would cause
 		 * errors again and again. Well, lets switch to R/O mode.
 		 */
 		goto out_ro;
-	}
 
 	/* It is %-EIO, the PEB went bad */
 



  parent reply	other threads:[~2012-01-24  0:12 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-23 23:42 [00/27] 2.6.32.55-longterm review Greg KH
2012-01-23 23:40 ` [01/27] ext4: fix undefined behavior in ext4_fill_flex_info() Greg KH
2012-01-23 23:40 ` [02/27] ALSA: snd-usb-us122l: Delete calls to preempt_disable Greg KH
2012-01-23 23:40 ` [03/27] ALSA: ice1724 - Check for ac97 to avoid kernel oops Greg KH
2012-01-23 23:40 ` [04/27] ALSA: hda - Return the error from get_wcaps_type() for invalid NIDs Greg KH
2012-01-23 23:40 ` [05/27] HID: bump maximum global item tag report size to 96 bytes Greg KH
2012-01-23 23:40 ` Greg KH [this message]
2012-01-23 23:40 ` [07/27] PCI: Fix PCI_EXP_TYPE_RC_EC value Greg KH
2012-01-23 23:40 ` [08/27] PCI: msi: Disable msi interrupts when we initialize a pci device Greg KH
2012-01-23 23:40 ` [09/27] xen/xenbus: Reject replies with payload > XENSTORE_PAYLOAD_MAX Greg KH
2012-01-23 23:40 ` [10/27] ima: free duplicate measurement memory Greg KH
2012-01-23 23:40 ` [11/27] PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB Greg KH
2012-01-23 23:40 ` [12/27] x86: Fix mmap random address range Greg KH
2012-01-23 23:40 ` [13/27] UBI: fix nameless volumes handling Greg KH
2012-01-23 23:41 ` [14/27] i2c: Fix error value returned by several bus drivers Greg KH
2012-01-23 23:41 ` [15/27] [media] V4L/DVB: v4l2-ioctl: integer overflow in video_usercopy() Greg KH
2012-01-23 23:41 ` [16/27] svcrpc: fix double-free on shutdown of nfsd after changing pool mode Greg KH
2012-01-23 23:41 ` [17/27] svcrpc: destroy server sockets all at once Greg KH
2012-01-23 23:41 ` [18/27] nfsd: Fix oops when parsing a 0 length export Greg KH
2012-01-23 23:41 ` [19/27] USB: cdc-wdm: fix misuse of logical operation in place of bitop Greg KH
2012-01-23 23:41 ` [20/27] [S390] fix cputime overflow in uptime_proc_show Greg KH
2012-01-23 23:41 ` [21/27] USB: Fix bad dma problem on WDM device disconnect Greg KH
2012-01-23 23:41 ` [22/27] block: add and use scsi_blk_cmd_ioctl Greg KH
2012-01-23 23:41 ` [23/27] kernel.h: add printk_ratelimited and pr_<level>_rl Greg KH
2012-01-24 14:46   ` Phil Carmody
2012-01-24 16:35     ` Ben Hutchings
2012-01-24 16:43       ` Greg KH
2012-01-23 23:41 ` [24/27] ALSA: HDA: Fix internal microphone on Dell Studio 16 XPS 1645 Greg KH
2012-01-23 23:41 ` [25/27] [SCSI] sym53c8xx: Fix NULL pointer dereference in slave_destroy Greg KH
2012-01-23 23:41 ` [26/27] score: fix off-by-one index into syscall table Greg KH
2012-01-23 23:41 ` [27/27] kprobes: initialize before using a hlist Greg KH

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