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 549582D24B7 for ; Sat, 4 Jul 2026 06:42:58 +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=1783147379; cv=none; b=dnYel7JdG5ZhvHkAMmCSpGVTvXX+atviG6j7T+MugVVkpoFlT+b9hK2puC6WRK0If1JECACo/Ah/7kzdtUv3J6OAzNkD4NMtec6gIWN+dKu8QnLw8ioOS96JG0TXTBpDnQWHMxL64Sd7/5Zs3qrrnC7aGXYNycY/1mk3z2+sxlU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783147379; c=relaxed/simple; bh=jrAFTMtABlHoVb1YoTZM0MiOGOnfngkz8WX9zqQ3Osg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=F6a0PRtF3RIM3aNlzkPRwKkH9wpHhftyP3wnCN0aioJikoaXuaKj5tgI+hCWxifMi9z+kPrCe7uUSs/p/MBS23Mofh57YUKnSNaQV5ZfkqF+MVyagSfwJL11Yrc1FCZZ8ok9l55LAKnFo5quH+JcbtJ8T6yM3NeWJjEC/jVPqlQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YLpIs6yb; 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="YLpIs6yb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E32DB1F000E9; Sat, 4 Jul 2026 06:42:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783147378; bh=gAV+ZwTlVxovv2UH+ZeI5s4MGQIDT9dk7McWDKKaZC0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=YLpIs6ybhVf+B/n2/j6llRPD2ubb+mpucZ5Efv7gOgywjdkYCn3RyjDd+csYagmW5 hJCLfPAFN8M+dq+D5Z7m/HuuxC9OcjiApGvc2IDoyiAwrM711rMV41Mt8Wm8bzJYnt OArk7F3vP8yvp0Hn0ljEM3IjIzihlE0lbaRkjO4m2R8N2/mcU1IIhI0BvnAl+Z3BVw xxXbywXflA8oZqWOkeo4D0Ka4S90JaxnYFPWv9JuvV3Yi7q+ZIygdv5yJdQ2lGgzq1 kAQ3I+qR1MzN+8cexMbh02r1n3jHKjc+AglOZYW7BJ1N/xQ0gELP1dJ8u7dsxreq0G +cKk5LH3gXdpw== Date: Sat, 4 Jul 2026 09:42:51 +0300 From: Mike Rapoport To: Brendan Jackman Cc: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/secretmem: disable under HIGHMEM Message-ID: References: <20260703-secretmem-highmem-v1-1-30d5ff944664@google.com> 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=us-ascii Content-Disposition: inline In-Reply-To: <20260703-secretmem-highmem-v1-1-30d5ff944664@google.com> On Fri, Jul 03, 2026 at 02:48:26PM +0000, Brendan Jackman wrote: > secretmem_fault() allocates a folio with GFP_HIGHUSER and then calls > set_direct_map_valid_noflush() without checking folio_test_highmem(). > This causes a warning and process crash (vibe-coded reproducer in Link > below): > > Link: https://github.com/bjackman/limmat-kernel-nix/commit/7b2acba2d3a5ef01400d493a155beb1d135b6bb5 > Fixes: 1507f51255c9f ("mm: introduce memfd_secret system call to create "secret" memory areas") > Signed-off-by: Brendan Jackman Reviewed-by: Mike Rapoport (Microsoft) -- Sincerely yours, Mike.