From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AFA6A37417B for ; Sat, 4 Jul 2026 02:05:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783130759; cv=none; b=cEdCkKH7Q90X5KI+ZyZXUHaX1ES4WzUzKYBeu4raroW6KjJPh9NyQNOfUu6CD6lD8Kbf94BU8/rEMxAjaWbQnLsGM2CekarvJffKr9RWc07L4N4f9iViBJcrOnRahivvZB6aa2XoihqiwdIDRjVmzzAq3QqOhXa+QXGgLjNGbxc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783130759; c=relaxed/simple; bh=0SBaxO5/pmCH0IZwTj2aF8Jd0HnqR128Z9b9x5xBzdI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qK22eT/BY9ftADpyqZBH6aaVQY9N4coklS/k5/Z5T7PHZMJ+U5paX/OGKgROu3u6LtnFkKuc3JUQvAvM0GxXinOi4/HJTNVKhMcTYNEyZbolcEAGDjMipUpuTrCyet0bHJSTudQxLtjBbnzsN7YYuQqNq9X21lY6Oiru0jBvhZo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IM6lCFYi; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IM6lCFYi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 300B71F000E9; Sat, 4 Jul 2026 02:05:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783130758; bh=S+jPVpO8HgqEG5QyURsNJkyTQKF7Uh4pH9HdG2N9Vbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IM6lCFYiM/qPPdfCxplXL80sveitjupd02VPhc1rYdSE+uUFJ97DsozFfqb8YsPdg 49Y5CKNdh7Wr89hvsxn7H4QJjPLvv5X+hS034nSnePiL2ShE96OTpopmm69LOjEJkg FYQXSmOln/HpnLXV6Qy1BBk2Duhgk46ct0+f591rHajewERYY8EGI6gTFpZsBh7v8g 1+NVIRdKse/Qf2FYRwFZzhV27ve8dECoXOdJczIjyRqe9psGZxpJUxSJmMsQZ//KIW xUeZvdd4gnYXpAvEhl45OLi2fAt0FEOgDhLKz48lAv+p/uJB4+CZGkhSaNscGyL1aB G0potOg9NYowg== From: Sasha Levin To: stable@vger.kernel.org Cc: Sasha Levin , Sashiko AI review , Lorenzo Stoakes , David Hildenbrand , Michal Hocko , Mike Rapoport , Peter Xu , Suren Baghdasaryan , Vlastimil Babka , Balbir Singh , Andrew Morton , Kiryl Shutsemau Subject: Re: [PATCH 5.10.y] userfaultfd: gate must_wait writability check on pte_present() Date: Fri, 3 Jul 2026 22:05:18 -0400 Message-ID: <2026070315-stable-reply-0024@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260702154859.975356-1-kas@kernel.org> References: <20260702154859.975356-1-kas@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, Jul 02, 2026 at 16:48:59 +0100, Kiryl Shutsemau wrote: > userfaultfd_must_wait() and userfaultfd_huge_must_wait() read the PTE > without taking the page table lock and then apply pte_write() / > huge_pte_write() to it. Those accessors decode bits from the present > encoding only; on a swap or migration entry they read the offset bits that > happen to share the same position and return an undefined result. Queued for 5.10.y, thanks! -- Thanks, Sasha