From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794047112; b=EbEBSe5uHafQtD5gTDfRtd2aiFpYgUlm8RJbT9juHDIBalbudj92gLY9NnEgSeMP5U8E CSM4t1QIl5Fd31djZS8mNnxWwKq1HJMbUEjlFe2xgYrIbA8IecP6VEHLGxpDOdmzn49BQ //qcm6tEvzjdSPCCD5Idqc2uS5T7CYf0IA6WT+W5HHzD5bnIwZgPAW9Ivz7555Qf8zREF Tmy9WjOuwQE/wvqj2D3FaOg23t5J2qdLZ/FgnXSicWoEgnGtSH00YIB2nHeOL8Ke0LEDn 1zoE7lI4NkjcppMM3SkRP5btYnV273ilYOQ9dGhZMjPlZCp2ogoQ0UCIaUHtO+K3Bvg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047112; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=i+bPh3tZnZLmK6BzqTr+483Uxt7U8dxJqnJFm3NXQU0=; b=5tAMvjYQhx5dVcEiLWPO1vHZR40O++V3R6vfg3WykVKFhQyk6w5GMw0l3wl7s/owB7Rm PpBwNLHlTb9qk4HNTpb0oxE3E+dXaVtriPsG6w6ZWDZB6gzxu63PCmQJxvvB8Zpz113rm UvlvclfND5+LMKCpBxtcwaGFkd8xQuPEC8YLy17t2ZEL8FibdQ+ZReeWcBDPx5wqOV+/Y PFeLiO3XpeqbPkTx5sAn2dnonvX9XJH8fVooudH/kVPdWnz+3pEkIGrYiNHP8XLpKball 11d8Emp20svD/J7lm9FSh+2NxL5MB48vFwEJWXbH0hUK44vX42XfFbsYXBF9/LdA1Lg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GOwAshV0; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BF347606A326 for ; Sat, 7 Nov 2026 10:25:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GOwAshV0 Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED10C1F0089F; Sat, 7 Nov 2026 10:25:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047111; bh=i+bPh3tZnZLmK6BzqTr+483Uxt7U8dxJqnJFm3NXQU0=; h=From:To:Cc:Subject:Date; b=GOwAshV0t3vZ8MG63CEU/nD+HZBNh9XUGNFRaxubebIcEnVdu09bf8abXoXnko0vS u6FzA6UFjwVdfXhWKT3ZkMqy+RtroHelMJI7M1TrF4qmZCuJDc8fjJfy9e+SUnz8JG yOUNbcZqZgBCYV/rtqUiIttdt26+ibZkvogh59cfS1GeHHTvNMOl8gNMe4kGmIZd1x +c7n6uwhn8H+FTUra8rWFwOhRrYrPiR2Gk1OWxhwciZ4WM3HXHA+fUbRotbPrJLHML mOMEhSI8hddXj9+mw6wzcuePTJKkSFrJK5+vQoxANCFZ3fTyRq54du9zHPl1bkwPH5 83k/wjsvNzvjg== From: Sasha Levin To: chizhiling@kylinos.cn, linkinjeon@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] exfat: advance valid_size to EOF for append writes" failed to apply to 6.12-stable tree Date: Sat, 7 Nov 2026 05:25:09 -0500 Message-ID: <20261107052509-failed-6.12-b70ab4075037@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x b70ab407503706289163dd59f1ac3e942bacc37d # git commit -s git send-email --to '' --in-reply-to '20261107052509-failed-6.12-b70ab4075037@kernel.org' --subject-prefix 'PATCH 6.12.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From b70ab407503706289163dd59f1ac3e942bacc37d Mon Sep 17 00:00:00 2001 From: Chi Zhiling Date: Sun, 4 Oct 2026 18:19:30 +0800 Subject: [PATCH] exfat: advance valid_size to EOF for append writes For an append write, the write position is recalculated by generic_write_checks(). Therefore, the write position must be obtained after generic_write_checks() returns. Using the original write position to advance valid_size may cause the valid_size update to be skipped, potentially exposing stale data. Also move the truncate_pagecache() check below the recalculated position, so that pos is never read before it is assigned. Fixes: 11a347fb6cef ("exfat: change to get file size from DataLength") Cc: stable@vger.kernel.org Signed-off-by: Chi Zhiling Signed-off-by: Namjae Jeon --- fs/exfat/file.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/fs/exfat/file.c b/fs/exfat/file.c index 3867e78c23125..87afb6bffd353 100644 --- a/fs/exfat/file.c +++ b/fs/exfat/file.c @@ -854,8 +854,7 @@ static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter) struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); struct exfat_inode_info *ei = EXFAT_I(inode); - loff_t pos = iocb->ki_pos; - loff_t valid_size; + loff_t pos, valid_size; int err; if (unlikely(exfat_forced_shutdown(inode->i_sb))) @@ -863,11 +862,6 @@ static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter) inode_lock(inode); - if (pos > i_size_read(inode)) - truncate_pagecache(inode, i_size_read(inode)); - - valid_size = ei->valid_size; - ret = generic_write_checks(iocb, iter); if (ret <= 0) goto unlock; @@ -878,6 +872,11 @@ static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter) goto unlock; } + pos = iocb->ki_pos; + if (pos > i_size_read(inode)) + truncate_pagecache(inode, i_size_read(inode)); + + valid_size = ei->valid_size; if (pos > valid_size) { ret = exfat_extend_valid_size(inode, pos); if (ret < 0 && ret != -ENOSPC) { @@ -887,6 +886,8 @@ static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter) } if (ret < 0) goto unlock; + + pos = valid_size; } if (iocb->ki_flags & IOCB_DIRECT) @@ -899,9 +900,6 @@ static ssize_t exfat_file_write_iter(struct kiocb *iocb, struct iov_iter *iter) inode_unlock(inode); - if (pos > valid_size) - pos = valid_size; - if (iocb->ki_pos > pos) { ssize_t err = generic_write_sync(iocb, iocb->ki_pos - pos); -- 2.53.0