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Tue, 09 Jun 2026 03:29:38 -0700 (PDT) From: Sanghyun Park To: yonghong.song@linux.dev, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org Cc: Sanghyun Park , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, puranjay@kernel.org Subject: Re: [PATCH v2] bpf: Fix use-after-free on mm_struct in bpf_find_vma() Date: Tue, 9 Jun 2026 19:26:15 +0900 Message-ID: <20260609102618.3508682-2-sanghyun.park.cnu@gmail.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hello Yonghong, Thank you for the feedback. You are right on both points. In v3 I will drop get_task_mm()+mmput() and instead mirror the pattern from upstream commit d8e27d2d22b6 ("bpf: fix mm lifecycle in open-coded task_vma iterator"): use spin_trylock(&task->alloc_lock) to read task->mm and mmget() to pin it, then release the reference with mmput_async(). I will also reject irqs-disabled contexts and !CONFIG_MMU on the foreign path, and fix the whitespace damage. v3 coming shortly. Sincerely, Sanghyun