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[67.180.10.175]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-23de4323e2asm97829105ad.110.2025.07.14.16.58.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 14 Jul 2025 16:58:30 -0700 (PDT) Message-ID: <65df1f7e-9512-4527-bbe4-0cf10877f4ba@gmail.com> Date: Mon, 14 Jul 2025 16:58:29 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [cgroups?] WARNING in css_rstat_exit To: syzbot , cgroups@vger.kernel.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, mkoutny@suse.com, syzkaller-bugs@googlegroups.com, tj@kernel.org, Shakeel Butt References: <6874b1d8.a70a0220.3b380f.0051.GAE@google.com> Content-Language: en-US From: JP Kobryn In-Reply-To: <6874b1d8.a70a0220.3b380f.0051.GAE@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 7/14/25 12:29 AM, syzbot wrote: > syzbot has found a reproducer for the following issue on: > > HEAD commit: 5d5d62298b8b Merge tag 'x86_urgent_for_v6.16_rc6' of git:/.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11dabd82580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=84eae426cbd8669c > dashboard link: https://syzkaller.appspot.com/bug?extid=8d052e8b99e40bc625ed > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=162c47d4580000 #syz test diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index a723b7dc6e4e..e6c5c998ead6 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -5669,6 +5669,12 @@ static struct cgroup_subsys_state *css_create(struct cgroup *cgrp, init_and_link_css(css, ss, cgrp); + err = css_rstat_init(css); + if (err) { + ss->css_free(css); + goto err_out; + } + err = percpu_ref_init(&css->refcnt, css_release, 0, GFP_KERNEL); if (err) goto err_free_css; @@ -5678,10 +5684,6 @@ static struct cgroup_subsys_state *css_create(struct cgroup *cgrp, goto err_free_css; css->id = err; - err = css_rstat_init(css); - if (err) - goto err_free_css; - /* @css is ready to be brought online now, make it visible */ list_add_tail_rcu(&css->sibling, &parent_css->children); cgroup_idr_replace(&ss->css_idr, css, css->id); @@ -5697,6 +5699,7 @@ static struct cgroup_subsys_state *css_create(struct cgroup *cgrp, err_free_css: INIT_RCU_WORK(&css->destroy_rwork, css_free_rwork_fn); queue_rcu_work(cgroup_destroy_wq, &css->destroy_rwork); +err_out: return ERR_PTR(err); } --