From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 100D44AEE2; Thu, 26 Mar 2026 22:40:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774564804; cv=none; b=ptcgwP3lqjU7T2rlDry/xT4GSP8RWQb9d8Q8186MIZFduzIJgQJ+QiX9RkhmmxSxy48jx4c3OR4J0rygvkCGS8zKriNZcVgKitDy+WssSVxhmpPkrDhjRWuh0huR8AO+UgZfmb1EwwwWudzrb7vLPnXcra8snvfOj2acPMsBUp4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774564804; c=relaxed/simple; bh=iAtnxxCAUCkZUia1OWke1EBuVKK5bzRRupk8WbbWY34=; h=Date:To:From:Subject:Message-Id; b=vDyNftPKbGav8wBRmiBmswq6YcY18a+q0irAqRjIF8fyURRY/QhYVR9SvApqBX3SoFbcNjt8rLbn/yCqO8tzIluG6jciFaRvFX8W0dw7pcHRztSh7gjVNj9Cxwkt9LGICT7em2zeV2iwpzCrLh9UaHIDah904bv5BSAwVpHpLXI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=UXQkIYxP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="UXQkIYxP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD77CC19424; Thu, 26 Mar 2026 22:40:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1774564803; bh=iAtnxxCAUCkZUia1OWke1EBuVKK5bzRRupk8WbbWY34=; h=Date:To:From:Subject:From; b=UXQkIYxPTpGqzb1O64FwypTVaa7eRmzFL4gpssgoNjkLfyMsLwW2ahiOb+kJ8JgU8 vz0p2mSlO7jnHiqPOBbKzpk7QlduXSskiDoh3BaAmnYLJi1zzDt+f5xR6uVx318O0/ sb75l2OUuwGzzPZfDFRJW9+tIIaHUXMMrITLBYoA= Date: Thu, 26 Mar 2026 15:40:03 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,pmladek@suse.com,kees@kernel.org,dhowells@redhat.com,davidgow@google.com,lk@c--e.de,akpm@linux-foundation.org From: Andrew Morton Subject: + lib-scatterlist-fix-temp-buffer-in-extract_user_to_sg.patch added to mm-nonmm-unstable branch Message-Id: <20260326224003.DD77CC19424@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: lib/scatterlist: fix temp buffer in extract_user_to_sg() has been added to the -mm mm-nonmm-unstable branch. Its filename is lib-scatterlist-fix-temp-buffer-in-extract_user_to_sg.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-scatterlist-fix-temp-buffer-in-extract_user_to_sg.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: "Christian A. Ehrhardt" Subject: lib/scatterlist: fix temp buffer in extract_user_to_sg() Date: Thu, 26 Mar 2026 22:49:02 +0100 Instead of allocating a temporary buffer for extracted user pages extract_user_to_sg() uses the end of the to be filled scatterlist as a temporary buffer. Fix the calculation of the start address if the scatterlist already contains elements. The unused space starts at sgtable->sgl + sgtable->nents not directly at sgtable->nents and the temporary buffer is placed at the end of this unused space. A subsequent commit will add kunit test cases that demonstrate that the patch is necessary. Pointed out by sashiko.dev on a previous iteration of this series. Link: https://lkml.kernel.org/r/20260326214905.818170-3-lk@c--e.de Fixes: 018584697533 ("netfs: Add a function to extract an iterator into a scatterlist") Signed-off-by: Christian A. Ehrhardt Cc: David Howells Cc: [v6.5+] Cc: David Gow Cc: Kees Cook Cc: Petr Mladek Signed-off-by: Andrew Morton --- lib/scatterlist.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/lib/scatterlist.c~lib-scatterlist-fix-temp-buffer-in-extract_user_to_sg +++ a/lib/scatterlist.c @@ -1123,8 +1123,7 @@ static ssize_t extract_user_to_sg(struct size_t len, off; /* We decant the page list into the tail of the scatterlist */ - pages = (void *)sgtable->sgl + - array_size(sg_max, sizeof(struct scatterlist)); + pages = (void *)sg + array_size(sg_max, sizeof(struct scatterlist)); pages -= sg_max; do { _ Patches currently in -mm which might be from lk@c--e.de are lib-scatterlist-fix-length-calculations-in-extract_kvec_to_sg.patch lib-scatterlist-fix-temp-buffer-in-extract_user_to_sg.patch lib-kunit_iov_iter-fix-memory-leaks.patch lib-kunit_iov_iter-improve-error-detection.patch lib-kunit_iov_iter-add-tests-for-extract_iter_to_sg.patch