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Howlett" , Vlastimil Babka , Mike Rapoport , Michal Hocko Subject: Re: [PATCH RFC v3 3/4] ptrace: add ptracer_access_allowed() Message-ID: References: <20260520-work-task_exec_state-v3-0-69f895bc1385@kernel.org> <20260520-work-task_exec_state-v3-3-69f895bc1385@kernel.org> MIME-Version: 1.0 In-Reply-To: <20260520-work-task_exec_state-v3-3-69f895bc1385@kernel.org> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: e5czw5ZodV6rSaEBr9rJ3aOgmmwum0QCc18iKs7fuVs_1779462538 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Server: rspam11 X-Stat-Signature: 5xwqtgmkwo9abjyzboi411bay7btkifs X-Rspamd-Queue-Id: E6B98A000B X-Rspam-User: X-HE-Tag: 1779462546-847670 X-HE-Meta: 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 9FemAv7O XS4HtGEHvc02I6AE5yJ/fc+AL9xOjMrfb5FwwSzLJMtnPVHmdp6QdhXZ5ISR1q42hgddVGEheZQzVUBXBk4TVKZt1U0tu3oPZVZNgE1UMYozO87ZmgIT5zEm2bQfYAUbjUGTElPcaxezQBJ/VWTMq+37XpdG2NG3PpmaYzMe9V+90qli3P0cbKQMJt7x8MOnA+Y4qb5LysfA7yvq8OGPifoe+mYvmK979BK2+SYFuf9TMJcbv0HTxE7SWOPtOwNTjIuCLTrsVd/vXyYuDmIwSzjJMW/1hOPBX3ZuEREvsUndwAwwqRavY2nNp6eFrDPcCvCb0MxyF3oGSS66mHHLVJS0kCVt2B4YJHQ7qGPIv+lwov+oc5BKl9KecSDISpqo5BD9nHmo5nLKKRI/qyZsXYOldvmgRNX64ne8nCNKpuJbc2KY= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 05/20, Christian Brauner (Amutable) wrote: > > +bool ptracer_access_allowed(struct task_struct *tsk) > +{ > + const struct task_exec_state *es; > + > + if (!tsk->ptrace) > + return false; > + if (current != tsk->parent) > + return false; > + guard(rcu)(); Really minor nit feel, free to ignore... guard(rcu)(); if (ptrace_parent(tsk) != current) return false; ... With or without this series, I don't really understand why ptrace_access_vm() needs these security checks... And ptrace_parent(tsk) == current should be always true? Oleg.