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smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=dNl8kU2Z; arc=none smtp.remote-ip=91.218.175.49 Received: from mta0.migadu.com (out-49.mta0.migadu.com [91.218.175.49]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6159D60A5BD2 for ; Mon, 2 Nov 2026 11:22:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 6159D60A5BD2 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=dNl8kU2Z X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=rlYYUg5m282yLIStEKkIHTozLzxeQHV9wO/ECVNrg9o=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793618553; v=1; x=1794223353; b=dNl8kU2ZZnY7p+1AZb5FkPRPxnYNE0pNnRkYzfMXhsQ6nzU8z5o/GWyH69JI2jndGu8pOXov iCXfD2V18rj7VtN0dm54SEJgnoT8r9LSk12pObDE1JIpBZph6bgTHoxZAQEPzv45DOvyDH48795 PK/VAB0uVps+jfwrxgnpYmZo= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 0a735c2090dc6b54; Mon, 02 Nov 2026 11:22:32 +0000 X-Mizu-Trace-ID: 0a735c2090dc6b54 X-Migadu-Flow: FLOW_OUT From: Lance Yang To: david@kernel.org Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@kernel.org, qi.zheng@linux.dev, shakeel.butt@linux.dev, ljs@kernel.org, kasong@tencent.com, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, baoquan.he@linux.dev, baolin.wang@linux.alibaba.com, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, kees@kernel.org, peterz@infradead.org, jannh@google.com, pfalcato@suse.de, hughd@google.com, pasha.tatashin@soleen.com, pratyush@kernel.org, willy@infradead.org, jack@suse.cz, ziy@nvidia.com, lance.yang@linux.dev, riel@surriel.com, harry@kernel.org, apopple@nvidia.com, nico.pache@linux.dev, ryan.roberts@arm.com, dev.jain@arm.com, usama.arif@linux.dev, kas@kernel.org, matthew.brost@intel.com, jhubbard@nvidia.com, peterx@redhat.com, will@kernel.org, aneesh.kumar@kernel.org, npiggin@gmail.com, osalvador@suse.de, minchan@kernel.org, muchun.song@linux.dev, xu.xin@linux.dev, chengming.zhou@linux.dev, chrisl@kernel.org, shikemeng@huaweicloud.com, nphamcs@gmail.com, youngjun.park@lge.com, gourry@gourry.net, joshua.hahnjy@gmail.com, rakie.kim@sk.com, ying.huang@linux.alibaba.com, jgg@ziepe.ca, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, mason@kernel.org, stable@vger.kernel.org, skhawaja@google.com, usama.anjum@arm.com Subject: Re: [PATCH v3 20/47] mm/gup: fix clearing folios in memfd_pin_folios() Date: Mon, 2 Nov 2026 19:22:27 +0800 Message-ID: <20261102112227.62593-1-lance.yang@linux.dev> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20261031-fixes_core-v3-20-d6437171ecc3@kernel.org> References: <20261031-fixes_core-v3-20-d6437171ecc3@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Sat, Oct 31, 2026 at 10:39:49AM +0100, David Hildenbrand (Arm) wrote: >From: Chris Mason > >memfd_pin_folios() pins folios obtained directly from the page cache >without checking whether they are uptodate. However, shmem fallocate() >can leave newly allocated folios uncleared and not uptodate. Callers >such as udmabuf can then expose uninitialized memory to userspace. Right, just make sure the folios are initialized before handing them to callers. They shouldn't have to care whether shmem deferred the clearing ;) >Clear non-uptodate folios and mark them uptodate under the folio lock >before returning them to the caller. > >Fix generated by an LLM and sent by Chris Mason in private. > >Fixes: 89c1905d9c14 ("mm/gup: introduce memfd_pin_folios() for pinning memfd folios") >Cc: stable@vger.kernel.org >Signed-off-by: Chris Mason >[ david: simplify description and comment ] >Reviewed-by: Pratyush Yadav (Google) >Reviewed-by: Samiullah Khawaja >Tested-by: Samiullah Khawaja >Tested-by: Muhammad Usama Anjum >Signed-off-by: David Hildenbrand (Arm) >--- LGTM! Reviewed-by: Lance Yang