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=1794065268; b=kneZ9fDF7A8qBFWz7xUhkSScM85a+xGYmOA/C8ot0nvFoipODOdoMe9dw7YMKn7GxvXG v3Ji4d+PgmOwE/roCr/RxIr9deM7+9JeyQI0Q/XGAC6paX61o+3moVhC1Cu0bkS066BCB 6VXWuHQoi+eQBZdDxHe0RmMVpjyCMaoIvts0JO0oWpjylP57ia7ejp5HxXNvCjwymuLah f6f/+LgPGrStlkUFgwm7HCUzQs/rEI5+Ony5+m4aHzXyLjwHaqOyricXxQjAN/lDyDRmA XgkLYLXd6930psYcWdV5zqk9UGnNo7YYUbT4BwTQFACa2CrbUig4I/fZ6fvCG/2Webw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794065268; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=vTknceZ8/+cmc0AtK4MW+TBmN5cO4Q57JaBEgewfFu0=; b=aEjxmTOzf7MsLkD+ct6Fdg/EVF3lQlsoZbVevg/DGFM33CIeb03Mdwgql07hldicHzlM 5tsppfmmhXHebLsnJux0I8LrrMaNZKgRf3AkJ67Gv1KSvT5Prc0T28+qYdmOnsDij4fEf 0HXCeQcHF1XD+rRQ+/MZuDQYnEgyn1Klr8lhAIWVcIiYEv4+cNiI1y9lzTKP8thrXHRQ1 Ge9+RquGFBjy1OZ2MnCah89qFnoBLgQFQbN/DIo6WtI9hnrEpfovnYUGRAI0Vc50RZNjx jgiUGygBFJ9j6cfMqxlKTNPmjIIaqokL0H2vcRRBlVwQ3Xd51nrJnUqsVkcKya3U8mA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=J03fDY13; 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 977D1606A32C; Sat, 7 Nov 2026 15:27:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=J03fDY13 Received: by smtp.kernel.org (Postfix) with ESMTPSA id DABE81F0089F; Sat, 7 Nov 2026 15:27:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794065268; bh=vTknceZ8/+cmc0AtK4MW+TBmN5cO4Q57JaBEgewfFu0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=J03fDY131NJ7fwJFo+IMxuY0ee252KLUCmWG2YayWBL6wO1oXGue8TOuGqI9bIijn 63HxjhI2XFa//Q4YPZ7gu7y7Ocm7XRcHzHhyp4fkA5r1aQCXU3P7XNoHX5GwRU/Cau ACNgbhEYAIO/qTwFtnwFZrW33AWc+TPrf0dlvbK0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chi Zhiling , Namjae Jeon , Sasha Levin Subject: [PATCH 7.3 0983/1257] exfat: advance valid_size to EOF for append writes Date: Sat, 7 Nov 2026 08:54:39 -0500 Message-ID: <20261107135006.512567292@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134939.434104957@linuxfoundation.org> References: <20261107134939.434104957@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chi Zhiling [ Upstream commit b70ab407503706289163dd59f1ac3e942bacc37d ] 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 Signed-off-by: Sasha Levin --- 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 a2a9ee1a20048..b30aec858da6c 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