diff mbox series

[v4,2/8] blk-cgroup: Fix class @block_class's subsystem refcount leakage

Message ID 20241218-class_fix-v4-2-3c40f098356b@quicinc.com (mailing list archive)
State New, archived
Headers show
Series driver core: class: Fix bug and code improvements for class APIs | expand

Commit Message

Zijun Hu Dec. 18, 2024, 12:01 a.m. UTC 
From: Zijun Hu <quic_zijuhu@quicinc.com>

blkcg_fill_root_iostats() iterates over @block_class's devices by
class_dev_iter_(init|next)(), but does not end iterating with
class_dev_iter_exit(), so causes the class's subsystem refcount leakage.

Fix by ending the iterating with class_dev_iter_exit().

Fixes: ef45fe470e1e ("blk-cgroup: show global disk stats in root cgroup io.stat")
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
---
 block/blk-cgroup.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Tejun Heo Dec. 18, 2024, 4:39 p.m. UTC | #1 
On Wed, Dec 18, 2024 at 08:01:32AM +0800, Zijun Hu wrote:
> From: Zijun Hu <quic_zijuhu@quicinc.com>
> 
> blkcg_fill_root_iostats() iterates over @block_class's devices by
> class_dev_iter_(init|next)(), but does not end iterating with
> class_dev_iter_exit(), so causes the class's subsystem refcount leakage.
> 
> Fix by ending the iterating with class_dev_iter_exit().
> 
> Fixes: ef45fe470e1e ("blk-cgroup: show global disk stats in root cgroup io.stat")
> Reviewed-by: Michal Koutný <mkoutny@suse.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: stable@vger.kernel.org
> Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.
diff mbox series

Patch

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e68c725cf8d975f53703ecf6e6c50594076204c8..fb9858efdfe9443704cb9a239def0e08addf2518 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1138,6 +1138,7 @@  static void blkcg_fill_root_iostats(void)
 		blkg_iostat_set(&blkg->iostat.cur, &tmp);
 		u64_stats_update_end_irqrestore(&blkg->iostat.sync, flags);
 	}
+	class_dev_iter_exit(&iter);
 }
 
 static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s)