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[80.136.81.63]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-ae3f66e6f30sm152102866b.33.2025.07.04.03.41.04 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Fri, 04 Jul 2025 03:41:04 -0700 (PDT) From: Laura Brehm X-Google-Original-From: Laura Brehm To: brauner@kernel.org Cc: laurabrehm@hey.com, laurajfbrehm@gmail.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] coredump: fix race condition between connect and Date: Fri, 4 Jul 2025 12:40:42 +0200 Message-Id: <20250704104042.86223-1-laurabrehm@hey.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20250704-ernten-fehlschlag-05a175183e12@brauner> References: <20250704-ernten-fehlschlag-05a175183e12@brauner> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit > kernel_connect() > -> sock->ops->connect::unix_stream_connect() > -> prepare_peercred() > -> pidfs_register_pid() Ah, thank you! I initially ran into this while working from an older tree that had had the coredump-socket series cherry-picked into it, but it was missing Commit fd0a109a0f6b7524543d17520da92a44a9f5343c ("net, pidfs: prepare for handing out pidfds for reaped sk->sk_peer_pid"). My tree instead had: static void init_peercred(struct sock *sk) { sk->sk_peer_pid = get_pid(task_tgid(current)); sk->sk_peer_cred = get_current_cred(); } I switched over to the main tree when preparing patches, but missed that the issue was not present there. > Honestly curious: is that something you actually observed or that you > think may happen or that an some coding assistant thinks might happen? No coding assistants (not a fan), but I understand the question. I maintain some other large projects and we get a few inane patches too. I usually try my best to avoid making patches such as these without some amount of double checking if I'm addressing a real issue, but I did run into the issue I described (about half the time, depending on how fast the coredump server ran) in my tree, and I forgot to repro after switching trees. Apologies for the inconvenience, and for the understanding/quick replies!