Messages in this thread | | | Date | Thu, 31 Mar 2016 10:15:16 +0200 | From | Johannes Thumshirn <> | Subject | Re: [PATCH v1] block: partition: initialize percpuref before new partition is visiable |
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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 <nkaje@codeaurora.org> > Tested-by: Naveen Kaje <nkaje@codeaurora.org> > Fixes: 6c71013ecb7e2(block: partition: convert percpu ref) > Cc: <stable@vger.kernel.org> # v4.3+ > Signed-off-by: Ming Lei <ming.lei@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 <jthumshirn@suse.de>
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