From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Ilya Dryomov <idryomov@gmail.com>,
Alex Elder <elder@linaro.org>
Subject: [PATCH 3.14 19/37] rbd: dont leak parent_spec in rbd_dev_probe_parent()
Date: Fri, 6 Nov 2015 11:24:34 -0800 [thread overview]
Message-ID: <20151106192411.887108258@linuxfoundation.org> (raw)
In-Reply-To: <20151106192410.681850286@linuxfoundation.org>
3.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ilya Dryomov <idryomov@gmail.com>
commit 1f2c6651f69c14d0d3a9cfbda44ea101b02160ba upstream.
Currently we leak parent_spec and trigger a "parent reference
underflow" warning if rbd_dev_create() in rbd_dev_probe_parent() fails.
The problem is we take the !parent out_err branch and that only drops
refcounts; parent_spec that would've been freed had we called
rbd_dev_unparent() remains and triggers rbd_warn() in
rbd_dev_parent_put() - at that point we have parent_spec != NULL and
parent_ref == 0, so counter ends up being -1 after the decrement.
Redo rbd_dev_probe_parent() to fix this.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
[idryomov@gmail.com: backport to < 4.2: rbd_dev->opts]
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/block/rbd.c | 35 +++++++++++++++--------------------
1 file changed, 15 insertions(+), 20 deletions(-)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4825,41 +4825,36 @@ out_err:
static int rbd_dev_probe_parent(struct rbd_device *rbd_dev)
{
struct rbd_device *parent = NULL;
- struct rbd_spec *parent_spec;
- struct rbd_client *rbdc;
int ret;
if (!rbd_dev->parent_spec)
return 0;
- /*
- * We need to pass a reference to the client and the parent
- * spec when creating the parent rbd_dev. Images related by
- * parent/child relationships always share both.
- */
- parent_spec = rbd_spec_get(rbd_dev->parent_spec);
- rbdc = __rbd_get_client(rbd_dev->rbd_client);
- ret = -ENOMEM;
- parent = rbd_dev_create(rbdc, parent_spec);
- if (!parent)
+ parent = rbd_dev_create(rbd_dev->rbd_client, rbd_dev->parent_spec);
+ if (!parent) {
+ ret = -ENOMEM;
goto out_err;
+ }
+
+ /*
+ * Images related by parent/child relationships always share
+ * rbd_client and spec/parent_spec, so bump their refcounts.
+ */
+ __rbd_get_client(rbd_dev->rbd_client);
+ rbd_spec_get(rbd_dev->parent_spec);
ret = rbd_dev_image_probe(parent, false);
if (ret < 0)
goto out_err;
+
rbd_dev->parent = parent;
atomic_set(&rbd_dev->parent_ref, 1);
-
return 0;
+
out_err:
- if (parent) {
- rbd_dev_unparent(rbd_dev);
+ rbd_dev_unparent(rbd_dev);
+ if (parent)
rbd_dev_destroy(parent);
- } else {
- rbd_put_client(rbdc);
- rbd_spec_put(parent_spec);
- }
-
return ret;
}
next prev parent reply other threads:[~2015-11-06 19:42 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-06 19:24 [PATCH 3.14 00/37] 3.14.57-stable review Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 01/37] ath9k: declare required extra tx headroom Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 02/37] iwlwifi: dvm: fix D3 firmware PN programming Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 03/37] iwlwifi: fix firmware filename for 3160 Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 04/37] iwlwifi: mvm: fix D3 firmware PN programming Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 05/37] iwlwifi: pci: add a few more PCI subvendor IDs for the 7265 series Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 06/37] iommu/amd: Dont clear DTE flags when modifying it Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 07/37] powerpc/rtas: Validate rtas.entry before calling enter_rtas() Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 08/37] ASoC: wm8904: Correct number of EQ registers Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 09/37] x86/setup: Extend low identity map to cover whole kernel range Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 10/37] mm: make sendfile(2) killable Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 14/37] drm/nouveau/gem: return only valid domain when theres only one Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 16/37] drm/radeon: dont try to recreate sysfs entries on resume Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 18/37] rbd: require stable pages if message data CRCs are enabled Greg Kroah-Hartman
2015-11-06 19:24 ` Greg Kroah-Hartman [this message]
2015-11-06 19:24 ` [PATCH 3.14 20/37] rbd: prevent kernel stack blow up on rbd map Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 21/37] Revert "ARM64: unwind: Fix PC calculation" Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 22/37] dm btree remove: fix a bug when rebalancing nodes after removal Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 23/37] dm btree: fix leak of bufio-backed block in btree_split_beneath error path Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 24/37] xhci: handle no ping response error properly Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 25/37] xhci: Add spurious wakeup quirk for LynxPoint-LP controllers Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 26/37] xen-blkfront: check for null drvdata in blkback_changed (XenbusStateClosing) Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 27/37] module: Fix locking in symbol_put_addr() Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 28/37] crypto: api - Only abort operations on fatal signal Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 29/37] md/raid1: submit_bio_wait() returns 0 on success Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 30/37] md/raid10: " Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 31/37] Revert "md: allow a partially recovered device to be hot-added to an array." Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 33/37] IB/cm: Fix rb-tree duplicate free and use-after-free Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 34/37] md/raid5: fix locking in handle_stripe_clean_event() Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 35/37] serial: 8250_pci: Add support for 16 port Exar boards Greg Kroah-Hartman
2015-11-23 14:23 ` Soeren Grunewald
2016-02-23 23:51 ` Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 36/37] serial: 8250_pci: Add support for 12 " Greg Kroah-Hartman
2015-11-06 19:24 ` [PATCH 3.14 37/37] xen: fix backport of previous kexec patch Greg Kroah-Hartman
2015-11-07 1:41 ` [PATCH 3.14 00/37] 3.14.57-stable review Guenter Roeck
2015-11-07 2:54 ` Shuah Khan
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