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| author | Kris Shannon <kris@shannon.id.au> | 2009-03-02 19:47:37 +1100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2009-03-05 12:04:57 +0100 |
| commit | a1a15ac5f9aeee521c048a88fc1aec848e623de7 (patch) | |
| tree | 964c1fe343bbc8edc24003df15dd475f1255e7e5 | |
| parent | 559595a985e106d2fa9f0c79b7f5805453fed593 (diff) | |
Fix kernel NULL pointer dereference in xen-blkfront
When booting Xen Dom0 on a pre-release 3.2.1 hypervisor the system Oopses on a
"Unable to handle kernel NULL pointer dereference" in xenwatch.
From the backtrace it looks like backend_changed is calling bdget_disk
with a NULL pointer. Checking for NULL and returning ENODEV instead
allows the kernel to boot.
| -rw-r--r-- | drivers/block/xen-blkfront.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index b6c8ce25435..8f905089b72 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -977,6 +977,8 @@ static void backend_changed(struct xenbus_device *dev, break; case XenbusStateClosing: + if (info->gd == NULL) + xenbus_dev_fatal(dev, -ENODEV, "gd is NULL"); bd = bdget_disk(info->gd, 0); if (bd == NULL) xenbus_dev_fatal(dev, -ENODEV, "bdget failed"); |