From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B681A3B2D1A; Wed, 30 Sep 2026 17:59:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790791171; cv=none; b=kpOo/RxxSwihhoofK7xgh+gT/X46wJ9Ur2K2rWUOfyhneRbabcUG7ZE/hgmWXshmYxjpfFZaU+thkIWWjnKr9p+o3MbjlaLYhvQXINJjlQTnLvB2ZytH5nOR9TZHhc036yG/rTIQAFF90IC4cESOUAxugymAUc4RlPCoO3967Cc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790791171; c=relaxed/simple; bh=TIahjvaUjWP5OgOTTGt5JX/y17BWxKPxjf8Pr7qFtSU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=quUO8qXRVbNEmawaXj4QWONbtmKCx2rioL4SNZNrLeL7VcnMWZ1PZf7H1ocxQJUwr1C0sxQ/Hs4VDKBy73Q70z71gEAh2Auqe5Kzp6RwUEQng5ux62Opy5oXHBenxYKModkJ3uccQVxTCUAuAsMk1FGhvQJVy2o63mZ1Dn9uXc8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GkkRjyVt; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GkkRjyVt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D16B1F000FF; Wed, 30 Sep 2026 17:59:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790791170; bh=2EPpeBaygn1w9Bu7EUscC5x+FZ0sf1xB/lB2wCX/8TA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GkkRjyVtiNDJGdjEpOO8S5eMlfe/V2J3yYs7sytyMPRUQvxvOnq9aYGPC4QQgGtcr nHkSvoQMtzdEhvS0N9RWTXLzsDr4rumXIc3zpjPE2Hjwzi0jLQY5Q81q6RqlGj1Oxp O6ES9m3gm9a8/CUr6kjqYrxmYkK45h6GxsMpbTlA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tejun Heo , Tao Cui , Jens Axboe , Sasha Levin Subject: [PATCH 5.15 208/752] blk-cgroup: fix leaks and online flag on radix_tree_insert failure Date: Wed, 30 Sep 2026 17:21:18 +0200 Message-ID: <20260930152402.732693810@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tao Cui [ Upstream commit dbbca20764382b4d411ec2918f4e278ffe547acc ] When radix_tree_insert() fails in blkg_create(), the error path has two issues: 1. blkg->online is set to true unconditionally, even when the blkg was never fully inserted. Move the assignment inside the success block. 2. The error path calls blkg_put() without first calling percpu_ref_kill(). Because the refcount is still in percpu mode, percpu_ref_put() only does this_cpu_sub() without checking for zero, so blkg_release() is never triggered. This permanently leaks the blkg memory, its percpu iostat, policy data, the parent blkg reference, and the cgroup css reference — the latter preventing the cgroup from ever being destroyed. Fix by replacing blkg_put() with percpu_ref_kill(), matching the pattern used in blkg_destroy(). Acked-by: Tejun Heo Signed-off-by: Tao Cui Link: https://patch.msgid.link/20260715132407.1469777-1-cui.tao@linux.dev Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-cgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 1179c4bee7052..4e8546adfce2b 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -296,15 +296,15 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, blkg->pd[i]->online = true; } } + blkg->online = true; } - blkg->online = true; spin_unlock(&blkcg->lock); if (!ret) return blkg; /* @blkg failed fully initialized, use the usual release path */ - blkg_put(blkg); + percpu_ref_kill(&blkg->refcnt); return ERR_PTR(ret); err_put_css: -- 2.53.0