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Thu, 04 Dec 2025 14:47:11 -0800 (PST) From: Jens Axboe To: Caleb Sander Mateos Cc: Joanne Koong , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20251204224332.1181383-1-csander@purestorage.com> References: <20251204224332.1181383-1-csander@purestorage.com> Subject: Re: [PATCH] io_uring/kbuf: use READ_ONCE() for userspace-mapped memory Message-Id: <176488843155.1025927.15790018424964919710.b4-ty@kernel.dk> Date: Thu, 04 Dec 2025 15:47:11 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Mailer: b4 0.14.3 On Thu, 04 Dec 2025 15:43:31 -0700, Caleb Sander Mateos wrote: > The struct io_uring_buf elements in a buffer ring are in a memory region > accessible from userspace. A malicious/buggy userspace program could > therefore write to them at any time, so they should be accessed with > READ_ONCE() in the kernel. Commit 98b6fa62c84f ("io_uring/kbuf: always > use READ_ONCE() to read ring provided buffer lengths") already switched > the reads of the len field to READ_ONCE(). Do the same for bid and addr. > > [...] Applied, thanks! [1/1] io_uring/kbuf: use READ_ONCE() for userspace-mapped memory commit: 78385c7299f7514697d196b3233a91bd5e485591 Best regards, -- Jens Axboe