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Biederman" , Tycho Andersen , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/2] pidfd: change pidfd_send_signal() to respect PIDFD_THREAD Message-ID: <20240214123655.GB16265@redhat.com> References: <20240209-stangen-feuerzeug-17c8662854c9@brauner> <20240209154305.GC3282@redhat.com> <20240209-radeln-untrennbar-9d4ae05aa4cc@brauner> <20240209155644.GD3282@redhat.com> <20240210-abfinden-beimessen-2dbfea59b0da@brauner> <20240210123033.GA27557@redhat.com> <20240210-dackel-getan-619c70fefa62@brauner> <20240210131518.GC27557@redhat.com> <20240210-chihuahua-hinzog-3945b6abd44a@brauner> <20240210165133.GD27557@redhat.com> Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240210165133.GD27557@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 On 02/10, Oleg Nesterov wrote: > > On 02/10, Christian Brauner wrote: > > > > + if (type == PIDFD_SIGNAL_PROCESS_GROUP) > > + ret = kill_pgrp_info(sig, &kinfo, pid); > > I guess you meant > > if (type == PIDTYPE_PGID) > > other than that, > > Reviewed-by: Oleg Nesterov Yes, but there is another thing I hadn't thought of... sys_pidfd_send_signal() does /* Only allow sending arbitrary signals to yourself. */ ret = -EPERM; if ((task_pid(current) != pid) && (kinfo.si_code >= 0 || kinfo.si_code == SI_TKILL)) goto err; and I am not sure that task_pid(current) == pid should allow the "arbitrary signals" if PIDFD_SIGNAL_PROCESS_GROUP. Perhaps /* Only allow sending arbitrary signals to yourself. */ ret = -EPERM; if ((task_pid(current) != pid || type == PIDTYPE_PGID) && (kinfo.si_code >= 0 || kinfo.si_code == SI_TKILL) goto err; ? Oleg.