From d1248436cbef1f924c04255367ff4845ccd9025e Mon Sep 17 00:00:00 2001 From: Zijun Hu Date: Sun, 5 Jan 2025 16:34:03 +0800 Subject: [PATCH] blk-cgroup: Fix class @block_class's subsystem refcount leakage MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Cc: Greg Kroah-Hartman Cc: stable@vger.kernel.org Acked-by: Tejun Heo Signed-off-by: Zijun Hu Link: https://lore.kernel.org/r/20250105-class_fix-v6-2-3a2f1768d4d4@quicinc.com Signed-off-by: Greg Kroah-Hartman --- block/blk-cgroup.c | 1 + 1 file changed, 1 insertion(+) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 45a395862fbc8..f1cf7f2909f3a 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) -- 2.47.2