From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from cae.in-ulm.de (cae.in-ulm.de [217.10.14.231]) (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 01788317147 for ; Thu, 26 Mar 2026 21:50:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.10.14.231 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774561805; cv=none; b=u5S9flPvtHcupqk8IdiJKMA9IXFOjw2ualrHjkiEpyzjEsL+U0yJY8RsJ3l1KWosFvoxI6ziGYXcBta9kh6WXsbyQZh91MXMFegsfRnJMiwg1f7QvNiDqQcKUWRTkKwPNEQN0/0rMr83X0LbmqvsNig6suClwn01EWTnU/8LF7o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774561805; c=relaxed/simple; bh=74taFH4nE6nxAxf28aCujS71x1vbG4wINVs7zn2Mi84=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=nsYCaLNLivh2nhW6U4vcg5iq8QsMZpiJI7cz4mSQfq3+5koa964FcSmDMCVpVzmPAzxctxYvx55rVY7t8JSK/RMijAucpAoPmWOVGt6vZ1M8BHkDEmgqaf+Ti6y/sIlFnDYuIBXwJ52XBnIPmGkWRxcItuO9GgEfro0uoArI9WU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=c--e.de; spf=pass smtp.mailfrom=c--e.de; arc=none smtp.client-ip=217.10.14.231 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=c--e.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=c--e.de Received: by cae.in-ulm.de (Postfix, from userid 1000) id E2953140041; Thu, 26 Mar 2026 22:49:51 +0100 (CET) From: "Christian A. Ehrhardt" To: David Howells , Andrew Morton , linux-kernel@vger.kernel.org Cc: "Christian A. Ehrhardt" , Kees Cook , Petr Mladek , David Gow Subject: [PATCH v3 0/5] Fix bugs in extract_iter_to_sg() Date: Thu, 26 Mar 2026 22:49:00 +0100 Message-Id: <20260326214905.818170-1-lk@c--e.de> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Fix bugs in the kvec and user variants of extract_iter_to_sg. This series is growing due to useful remarks made by sashiko.dev. The main bugs are: - The length for an sglist entry when extracting from a kvec can exceed the number of bytes in the page. This is obviously not intended. - When extracting a user buffer the sglist is temporarily used as a scratch buffer for extracted page pointers. If the sglist already contains some elements this scratch buffer could overlap with existing entries in the sglist. The series adds test cases to the kunit_iov_iter test that demonstrate all of these bugs. Additionally, there is a memory leak fix for the test itself. The bugs were orignally introduced into kernel v6.3 where the function lived in fs/netfs/iterator.c. It was later moved to lib/scatterlist.c in v6.5. Thus the actual fix is only marked for backports to v6.5+. --- Changes in v2: Addresss valid issues raised by AI review https://sashiko.dev/#/patchset/20260323212350.807118-1-lk@c--e.de: - Add kunit assertions for OOM conditions in the test - Reorder commits. - Fix sg_max == 0 case. - Fix return value if we run out of sg entries. - Adjust tests to catch these cases, too. Changes in v3: - Add fix and test for extract_user_to_sg() - Fix memory leak in the unit test. - Re-order commits: Code fixes first, then tests. --- Christian A. Ehrhardt (5): lib/scatterlist: Fix length calculations in extract_kvec_to_sg lib/scatterlist: Fix temp buffer in extract_user_to_sg() lib: kunit_iov_iter: Fix memory leaks lib: kunit_iov_iter: Improve error detection lib: kunit_iov_iter: Add tests for extract_iter_to_sg lib/scatterlist.c | 8 +- lib/tests/kunit_iov_iter.c | 224 +++++++++++++++++++++++++++++++++++-- 2 files changed, 221 insertions(+), 11 deletions(-) -- 2.43.0