diff options
| author | Bob Liu <bob.liu@oracle.com> | 2015-12-10 09:16:48 +0800 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2016-01-04 12:21:26 -0500 |
| commit | 93bb277f97a6d319361766bde228717faf4abdeb (patch) | |
| tree | 6cfb401fa392a96867579ac36bf5eb05826056cb /drivers/block/xen-blkback/xenbus.c | |
| parent | db6fbc106786f26d95889c50c18b1f28aa543a17 (diff) | |
xen/blkback: Fix two memory leaks.
This patch fixs two memleaks:
backtrace:
[<ffffffff817ba5e8>] kmemleak_alloc+0x28/0x50
[<ffffffff81205e3b>] kmem_cache_alloc+0xbb/0x1d0
[<ffffffff81534028>] xen_blkbk_probe+0x58/0x230
[<ffffffff8146adb6>] xenbus_dev_probe+0x76/0x130
[<ffffffff81511716>] driver_probe_device+0x166/0x2c0
[<ffffffff815119bc>] __device_attach_driver+0xac/0xb0
[<ffffffff8150fa57>] bus_for_each_drv+0x67/0x90
[<ffffffff81511ab7>] __device_attach+0xc7/0x120
[<ffffffff81511b23>] device_initial_probe+0x13/0x20
[<ffffffff8151059a>] bus_probe_device+0x9a/0xb0
[<ffffffff8150f0a1>] device_add+0x3b1/0x5c0
[<ffffffff8150f47e>] device_register+0x1e/0x30
[<ffffffff8146a9e8>] xenbus_probe_node+0x158/0x170
[<ffffffff8146abaf>] xenbus_dev_changed+0x1af/0x1c0
[<ffffffff8146b1bb>] backend_changed+0x1b/0x20
[<ffffffff81468ca6>] xenwatch_thread+0xb6/0x160
unreferenced object 0xffff880007ba8ef8 (size 224):
backtrace:
[<ffffffff817ba5e8>] kmemleak_alloc+0x28/0x50
[<ffffffff81205c73>] __kmalloc+0xd3/0x1e0
[<ffffffff81534d87>] frontend_changed+0x2c7/0x580
[<ffffffff8146af12>] xenbus_otherend_changed+0xa2/0xb0
[<ffffffff8146b2c0>] frontend_changed+0x10/0x20
[<ffffffff81468ca6>] xenwatch_thread+0xb6/0x160
[<ffffffff810d3e97>] kthread+0xd7/0xf0
[<ffffffff817c4a9f>] ret_from_fork+0x3f/0x70
[<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffff8800048dcd38 (size 224):
The first leak is caused by not put() the be->blkif reference
which we had gotten in xen_blkif_alloc(), while the second is
us not freeing blkif->rings in the right place.
Signed-off-by: Bob Liu <bob.liu@oracle.com>
Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/block/xen-blkback/xenbus.c')
| -rw-r--r-- | drivers/block/xen-blkback/xenbus.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 44396b8a0cb2..876763f7f13e 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -297,8 +297,16 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif) BUG_ON(ring->free_pages_num != 0); BUG_ON(ring->persistent_gnt_c != 0); WARN_ON(i != (XEN_BLKIF_REQS_PER_PAGE * blkif->nr_ring_pages)); + xen_blkif_put(blkif); } blkif->nr_ring_pages = 0; + /* + * blkif->rings was allocated in connect_ring, so we should free it in + * here. + */ + kfree(blkif->rings); + blkif->rings = NULL; + blkif->nr_rings = 0; return 0; } @@ -310,7 +318,6 @@ static void xen_blkif_free(struct xen_blkif *blkif) xen_vbd_free(&blkif->vbd); /* Make sure everything is drained before shutting down */ - kfree(blkif->rings); kmem_cache_free(xen_blkif_cachep, blkif); } @@ -484,7 +491,6 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle, static int xen_blkbk_remove(struct xenbus_device *dev) { struct backend_info *be = dev_get_drvdata(&dev->dev); - unsigned int i; pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); @@ -499,12 +505,11 @@ static int xen_blkbk_remove(struct xenbus_device *dev) dev_set_drvdata(&dev->dev, NULL); - if (be->blkif) { + if (be->blkif) xen_blkif_disconnect(be->blkif); - for (i = 0; i < be->blkif->nr_rings; i++) - xen_blkif_put(be->blkif); - } + /* Put the reference we set in xen_blkif_alloc(). */ + xen_blkif_put(be->blkif); kfree(be->mode); kfree(be); return 0; |