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 47BAF4086A; Thu, 20 Aug 2026 00:14:06 +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=1787184848; cv=none; b=c7Q5Djx/48zA8yYz7ZTYsKVVkjMn721vYTVn1ssAH2Kta1RVuJ5Zxma/kW+9ZzRF+AxwiVlEQXv28SqopowvCPEf17LBi1l9V9PalEbIbN/QVMKr8bDV3oCtCBmkCuUqN3lB7BcWstNFb98x7DRPQLSOfnKplmVK6fjWCAOqg18= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787184848; c=relaxed/simple; bh=hGpmloiCLdV24MFQD7/AXId11ujp9dU2vYxXpAaxRZc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RBL8m4EWdmJw5Y4hAkEnEMLyK33A5yM3/0H9EBrzW3IOG5/LXcC7QXYlotkMrQB91qFq+TqYLTu+UIoga0WaZhWswpH9n1NF6Sh4GyljXfZb2Y8mj0h9B6Uqi9hrosrt7cgxruuIWfbKDgo0GX7c4osvRXILtZP/nK5Z5IvP8P4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aAcEbQSR; 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="aAcEbQSR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A39601F000E9; Thu, 20 Aug 2026 00:14:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787184846; bh=HrAZoFB2O4ijHVXZLxifKgZ8fU8/Rsiq/ZvJdgv6ZAw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aAcEbQSRvUAdr33zTA4FXccyAXg1kygJsd4ah3MBPqCNU7I+IgvLQhsrZY0AUSjvC 4nlgQSrhQZlXPxhekgLQSirgnqyqvkBgyAg/f8tETcCmz3tSISyr60zD1MjjwzpPT/ lFnei0Wp3GVXDjUGhk3F7IZO10YADXCYMu19p81phqAZ8eckNmxoTTTRjKj++er/oW hVrhyFBXowh9pJc6ftyOkd8H+yoRnwz5kU7RJwEzQe4nAjoIbq6DwTQqUbvtxAmK5q eS8NgTadFlgfiwsn/kRP06Owzd4gBBkKcgZgtVd85ktUAKGm/1XDi4oyKMLab3/hVn z9wBt5zOf/jxw== From: SJ Park To: Anshuman Cc: SJ Park , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , Shuah Khan , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko Subject: Re: [PATCH] selftests/mm: check stat() return value in khugepaged get_finfo() Date: Wed, 19 Aug 2026 17:13:55 -0700 Message-ID: <20260820001356.87221-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260819121426.49500-1-anshumantewari123@gmail.com> 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 'get_maintainer.pl --nogit --nogit-fallback' suggests adding below recipients. I added them. - Zi Yan - Baolin Wang - "Liam R. Howlett" - Nico Pache - Ryan Roberts - Dev Jain - Barry Song - Lance Yang - Usama Arif - Vlastimil Babka - Mike Rapoport - Suren Baghdasaryan - Michal Hocko On Wed, 19 Aug 2026 17:44:26 +0530 Anshuman wrote: > get_finfo() calls stat() to get metadata about the target directory, > but never checks the return value. On failure, stat() returns -1 and > leaves path_stat unmodified, so path_stat.st_mode may contain > uninitialized stack data. > > The code then checks S_ISDIR(path_stat.st_mode) against this > potentially garbage value. This can produce a misleading "Not a > directory" error when the real problem is a nonexistent or > inaccessible path, or, in the worst case, the check could pass by > chance on garbage data and let the function continue using an > invalid path_stat for the rest of its logic. > > Check the return value and fail with a clear error message if > stat() fails, matching the error-handling style already used for > statfs() and read_file() later in the same function. Makes sense to me. > > Signed-off-by: Anshuman Reviewed-by: SJ Park Thanks, SJ [...]