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 8FFA327604E; Tue, 12 Aug 2025 19:00:34 +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=1755025234; cv=none; b=Px7JxLU6S6Gn7V0Gy1I9MvQPqC44z+FRFeOLMInM6arUoCtpf+PGOUByFtqPC5HUZnZUP/pxb6ow25etSj4JBoFdUwyH/788q0K7iDmLW4wk3TciRA+MNluLoAuKnNMqfO6v6nXXX4mjFUzjvrGVZONwXhd/cyyF3vZCYYd8pPc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755025234; c=relaxed/simple; bh=4jusQ+yWuvyLu67N0M1Zv8SClFPTVeHwKQgrDsnIpzU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kFujbnG/fq1lgdiwaIuWX6OtcdEnBKROBqxVxIRc1k1BQS3eNG0JuNU0/2zn78jQgCwCh5INalbDicihjxPAiGzyi+ITNFxPuFjPpf1k4SYvRX6xWzcHfamvGMbPbneAowiejboErbEye5pZaeWGy3kMXvxHfDV6jEUY8PW2Meo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dMXsGcqw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dMXsGcqw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B06DEC4CEF0; Tue, 12 Aug 2025 19:00:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755025234; bh=4jusQ+yWuvyLu67N0M1Zv8SClFPTVeHwKQgrDsnIpzU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dMXsGcqw1e2jJdeblp7FDMr3i0nlkR1GdclvqGtsYuGHoSClZ1p0PAG4y5afgrO0K MvdQX1bKXcfn49CFy72y9p3uuHXGUYMz6Fg4SuHw9QvyC75lZNOiJlqJwBfv8b7GcZ zA/IF059xQcyNziL4AQeiEbJH/8RT3pSKwnS4YXU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shinichiro Kawasaki , Christoph Hellwig , Jens Axboe Subject: [PATCH 6.16 609/627] zloop: fix KASAN use-after-free of tag set Date: Tue, 12 Aug 2025 19:35:04 +0200 Message-ID: <20250812173455.037556612@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250812173419.303046420@linuxfoundation.org> References: <20250812173419.303046420@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shin'ichiro Kawasaki commit 765761851d89c772f482494d452e266795460278 upstream. When a zoned loop device, or zloop device, is removed, KASAN enabled kernel reports "BUG KASAN use-after-free" in blk_mq_free_tag_set(). The BUG happens because zloop_ctl_remove() calls put_disk(), which invokes zloop_free_disk(). The zloop_free_disk() frees the memory allocated for the zlo pointer. However, after the memory is freed, zloop_ctl_remove() calls blk_mq_free_tag_set(&zlo->tag_set), which accesses the freed zlo. Hence the KASAN use-after-free. zloop_ctl_remove() put_disk(zlo->disk) put_device() kobject_put() ... zloop_free_disk() kvfree(zlo) blk_mq_free_tag_set(&zlo->tag_set) To avoid the BUG, move the call to blk_mq_free_tag_set(&zlo->tag_set) from zloop_ctl_remove() into zloop_free_disk(). This ensures that the tag_set is freed before the call to kvfree(zlo). Fixes: eb0570c7df23 ("block: new zoned loop block device driver") CC: stable@vger.kernel.org Signed-off-by: Shin'ichiro Kawasaki Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20250731110745.165751-1-shinichiro.kawasaki@wdc.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/zloop.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/block/zloop.c b/drivers/block/zloop.c index 553b1a713ab9..a423228e201b 100644 --- a/drivers/block/zloop.c +++ b/drivers/block/zloop.c @@ -700,6 +700,8 @@ static void zloop_free_disk(struct gendisk *disk) struct zloop_device *zlo = disk->private_data; unsigned int i; + blk_mq_free_tag_set(&zlo->tag_set); + for (i = 0; i < zlo->nr_zones; i++) { struct zloop_zone *zone = &zlo->zones[i]; @@ -1080,7 +1082,6 @@ static int zloop_ctl_remove(struct zloop_options *opts) del_gendisk(zlo->disk); put_disk(zlo->disk); - blk_mq_free_tag_set(&zlo->tag_set); pr_info("Removed device %d\n", opts->id); -- 2.50.1