On 2016-03-31 04:40, Ming Lei wrote:
The initialization of partition's percpu_ref should have been done
before
the new partition is updated to partition table via
rcu_assign_pointer(), otherwise the uninitialized percpu_ref may be
accessed
in data path.
This patch fixes this issue reported by Naveen.
Reported-by: Naveen Kaje <nk...@codeaurora.org>
Tested-by: Naveen Kaje <nk...@codeaurora.org>
Fixes: 6c71013ecb7e2(block: partition: convert percpu ref)
Cc: <sta...@vger.kernel.org> # v4.3+
Signed-off-by: Ming Lei <ming....@canonical.com>
---
V1:
- put 'if' around the actual device_remove_file at the label
as suggested by Christoph
- make commit log more accurate
block/partition-generic.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/block/partition-generic.c b/block/partition-generic.c
index 5d87019..54d4be8 100644
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -361,15 +361,17 @@ struct hd_struct *add_partition(struct gendisk
*disk, int partno,
goto out_del;
}
+ err = hd_ref_init(p);
+ if (err)
+ goto out_remove_file;
+
/* everything is up and running, commence */
rcu_assign_pointer(ptbl->part[partno], p);
/* suppress uevent if the disk suppresses it */
if (!dev_get_uevent_suppress(ddev))
kobject_uevent(&pdev->kobj, KOBJ_ADD);
-
- if (!hd_ref_init(p))
- return p;
+ return p;
out_free_info:
free_part_info(p);
@@ -378,6 +380,9 @@ out_free_stats:
out_free:
kfree(p);
return ERR_PTR(err);
+out_remove_file:
+ if (flags & ADDPART_FLAG_WHOLEDISK)
+ device_remove_file(pdev, &dev_attr_whole_disk);
out_del:
kobject_put(p->holder_dir);
device_del(pdev);
Looks good,
Reviewed-by: Johannes Thumshirn <jthumsh...@suse.de>
