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authorCathy Avery <cathy.avery@oracle.com>2015-10-02 09:35:01 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-11-09 14:33:37 -0800
commit89d8953e76da25abcc74e0934267f70977e79582 (patch)
treedabc91b6b57d4df40038f201a4a36c3563328057 /drivers/block
parent01d369942901be5e54715047d0b88936ced31197 (diff)
xen-blkfront: check for null drvdata in blkback_changed (XenbusStateClosing)
commit a54c8f0f2d7df525ff997e2afe71866a1a013064 upstream. xen-blkfront will crash if the check to talk_to_blkback() in blkback_changed()(XenbusStateInitWait) returns an error. The driver data is freed and info is set to NULL. Later during the close process via talk_to_blkback's call to xenbus_dev_fatal() the null pointer is passed to and dereference in blkfront_closing. Signed-off-by: Cathy Avery <cathy.avery@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/xen-blkfront.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 89c7371ab2dc..42ef86c409b6 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1925,7 +1925,8 @@ static void blkback_changed(struct xenbus_device *dev,
break;
/* Missed the backend's Closing state -- fallthrough */
case XenbusStateClosing:
- blkfront_closing(info);
+ if (info)
+ blkfront_closing(info);
break;
}
}