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imf28.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf28.hostedemail.com: domain of pulehui@huaweicloud.com designates 45.249.212.51 as permitted sender) smtp.mailfrom=pulehui@huaweicloud.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1748352102; a=rsa-sha256; cv=none; b=fUwdbFQHYrGpW7605hPspw0O1a7VEERe5UjOa7avoHEZqimtq9VxlU1LfsUe+5xDP/kS0E I4ooMdvvpkSSmveQAyMan03kXFLr0jRsubByvAkhXoyT2ztRDiCIgKfn2BPxIJCZ33Hlwm Wjrpl55rAhwrsBkC/qhr+HKRe7iM3IM= Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4b6CvF5rm4z4f3k5c for ; Tue, 27 May 2025 21:21:13 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.252]) by mail.maildlp.com (Postfix) with ESMTP id E86111A07BB for ; Tue, 27 May 2025 21:21:33 +0800 (CST) Received: from ultra.huawei.com (unknown [10.90.53.71]) by APP3 (Coremail) with SMTP id _Ch0CgBX98FavDVoK9fhNQ--.12329S4; Tue, 27 May 2025 21:21:33 +0800 (CST) From: Pu Lehui To: mhiramat@kernel.org, oleg@redhat.com, peterz@infradead.org, akpm@linux-foundation.org, Liam.Howlett@oracle.com, lorenzo.stoakes@oracle.com, vbabka@suse.cz, jannh@google.com, pfalcato@suse.de Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, pulehui@huawei.com Subject: [RFC PATCH v2 2/2] mm/mremap: Expose abnormal new_pte during move_ptes Date: Tue, 27 May 2025 13:23:51 +0000 Message-Id: <20250527132351.2050820-3-pulehui@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250527132351.2050820-1-pulehui@huaweicloud.com> References: <20250527132351.2050820-1-pulehui@huaweicloud.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:_Ch0CgBX98FavDVoK9fhNQ--.12329S4 X-Coremail-Antispam: 1UD129KBjvdXoW7Wr43Kry8tF13uF47ZFy5Arb_yoWfJrgE9r 4Fqr95tr4DAr1vyw15Cwn8urZIkw1qgr18XFnxtr92yr4kJan3ur929rWkZa9ruryj9rZ8 Wr4kJrWIgr1UKjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbDAYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7IE14v26r15M2 8IrcIa0xkI8VCY1x0267AKxVW5JVCq3wA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK 021l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r 4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx 0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWU JVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7AKxV WUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E 14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIx kGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAF wI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r 4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x07UCZXrU UUUU= X-CM-SenderInfo: psxovxtxl6x35dzhxuhorxvhhfrp/ X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 56EE8C000A X-Stat-Signature: i4nk7bdppqw9br93ma41ddt6eiz635qw X-Rspam-User: X-HE-Tag: 1748352099-543775 X-HE-Meta: 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 jajj7fwN SUJ6Q1dcjvhG6ZX6kSapOpI9hSvU6RdY9o6CyKxQuKYe1xtJ0oP3xK7Gu34+8pIwnntRVk+PLyKCIlfqoV6Ah2fEeVY13Lr0Sa8xlXDmiEbEy+E/RJzr1/U9uRqVDMsaJlqYIZWJoTWxBsp/aCRil70BDexJJ1U9BQrazN0xAKPA56TxfnufR0SNjKiPMYZs6lPy0mw7hptSB1NI= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Pu Lehui When executing move_ptes, the new_pte must be NULL, otherwise it will be overwritten by the old_pte, and cause the abnormal new_pte to be leaked. In order to make this problem to be more explicit, let's add WARN_ON_ONCE when new_pte is not NULL. Suggested-by: Oleg Nesterov Signed-off-by: Pu Lehui --- mm/mremap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/mremap.c b/mm/mremap.c index 83e359754961..adb3a111b5c1 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -237,6 +237,8 @@ static int move_ptes(struct pagetable_move_control *pmc, for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE, new_pte++, new_addr += PAGE_SIZE) { + WARN_ON_ONCE(!pte_none(*new_pte)) + if (pte_none(ptep_get(old_pte))) continue; -- 2.34.1