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Fri, 10 May 2019 12:14:59 -0700 (PDT) Received: from brauner.io ([212.91.227.56]) by smtp.gmail.com with ESMTPSA id i45sm1671806eda.67.2019.05.10.12.14.57 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 10 May 2019 12:14:58 -0700 (PDT) Date: Fri, 10 May 2019 21:14:57 +0200 From: Christian Brauner To: Oleg Nesterov Cc: jannh@google.com, viro@zeniv.linux.org.uk, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, arnd@arndb.de, arunks@codeaurora.org, cyphar@cyphar.com, dhowells@redhat.com, ebiederm@xmission.com, elena.reshetova@intel.com, guro@fb.com, keescook@chromium.org, luto@amacapital.net, luto@kernel.org, mhocko@suse.com, mingo@kernel.org, mtk.manpages@gmail.com, namit@vmware.com, peterz@infradead.org, riel@surriel.com, shakeelb@google.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de, wad@chromium.org, syzbot+3286e58549edc479faae@syzkaller.appspotmail.com Subject: Re: [PATCH] fork: do not release lock that wasn't taken Message-ID: <20190510191456.3gqfoyloezedn3ju@brauner.io> References: <20190510104913.27143-1-christian@brauner.io> <20190510153647.GB21421@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190510153647.GB21421@redhat.com> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 10, 2019 at 05:36:47PM +0200, Oleg Nesterov wrote: > On 05/10, Christian Brauner wrote: > > > > @@ -2102,7 +2102,7 @@ static __latent_entropy struct task_struct *copy_process( > > */ > > retval = cgroup_can_fork(p); > > if (retval) > > - goto bad_fork_put_pidfd; > > + goto bad_fork_cgroup_threadgroup_change_end; > > > > /* > > * From this point on we must avoid any synchronous user-space > > @@ -2217,11 +2217,12 @@ static __latent_entropy struct task_struct *copy_process( > > spin_unlock(¤t->sighand->siglock); > > write_unlock_irq(&tasklist_lock); > > cgroup_cancel_fork(p); > > +bad_fork_cgroup_threadgroup_change_end: > > + cgroup_threadgroup_change_end(current); > > bad_fork_put_pidfd: > > if (clone_flags & CLONE_PIDFD) > > ksys_close(pidfd); > > bad_fork_free_pid: > > - cgroup_threadgroup_change_end(current); > > if (pid != &init_struct_pid) > > free_pid(pid); > > bad_fork_cleanup_thread: > > Reviewed-by: Oleg Nesterov Thanks for the quick review, Oleg! :) Christian