From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C8E0DC79F82 for ; Sat, 5 Sep 2026 00:38:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1x2eQC-00034F-Qb; Fri, 04 Sep 2026 20:38:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x2eQA-00033e-NN; Fri, 04 Sep 2026 20:38:14 -0400 Received: from tor.source.kernel.org ([172.105.4.254]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x2eQ9-0008EZ-5W; Fri, 04 Sep 2026 20:38:14 -0400 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 6D974600E2; Sat, 5 Sep 2026 00:38:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC28F1F00A3D; Sat, 5 Sep 2026 00:38:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788568691; bh=jawrO9RQI5aekw18As+sD1SV4zeOkWBV0F+Sx6h56So=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=kZ53YqTiKXowkm5cH15Fl0W+Lh2muyONE4p/udDhCe3pseENPZQzaUbbxd1m2TkIK WIhJl4U33HDmQfO2kXCMJo0zjLW9+TCYp7GzHjqC3D7rjVd678H3a3K+6MgA1SZiU3 rPTKsDyqqe6zBQRqhfhFQgfR5kyKM+R/VbbkQMczLqWDGhfJBwGVF/ts+hJdADKBEO KKfIgnYE+YQbs77mrYj9/cmafY19kPlJFmrMFIVKMZ1pBvdC7zl9JtEdiGUH731DrV 9ogXtFwZB9+qA+d5ruoXN+zzsF7yV5wvIyWhh2fZPrcoIeqmyGv4VO85cNlFAxw4WJ aK7Ts/CkOIhrg== Message-ID: <08401f4f-1bb6-4445-b157-9135458d32ea@kernel.org> Date: Sat, 5 Sep 2026 09:38:08 +0900 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 12/12] file-posix: reject a zone append to a full or conventional zone To: Niklas Cassel , Stefan Hajnoczi , Kevin Wolf , Hanna Reitz , Fam Zheng Cc: Sam Li , qemu-block@nongnu.org, qemu-devel@nongnu.org References: <20260904161801.1568841-1-cassel@kernel.org> <20260904161801.1568841-13-cassel@kernel.org> Content-Language: en-US From: Damien Le Moal Organization: Western Digital Research In-Reply-To: <20260904161801.1568841-13-cassel@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=172.105.4.254; envelope-from=dlemoal@kernel.org; helo=tor.source.kernel.org X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 9/5/26 01:18, Niklas Cassel wrote: > raw_co_prw() replaces the offset of a zone append with the write pointer > of the addressed zone, which assumes that the stored value names a > position inside that zone. It does not in two cases. > > A full zone has its write pointer recorded at the end of the zone, since > get_zones_wp() stores start + len for BLK_ZONE_COND_FULL. That is the > first sector of the following zone, so the append is submitted there. The > kernel accepts it whenever that zone is empty, because it is a legal > write at its write pointer, and the completion path advances the wrong > zone because it recomputes the zone index from the replaced offset. The > data is written to a zone that was never addressed and success is > returned: > > zone 2 finished, then a 4 KiB append to zone 2: > After zap done, the append sector is 0x180000 <- zone 3 > zone 2: wptr 0x180000, zcond:14 (full) > zone 3: wptr 0x180008 <- advanced > > A conventional zone has no write pointer at all, and its array entry > carries only the type marker in the top bit, so the offset becomes > negative and the write fails with EINVAL. That is harmless but it reports > nothing about the actual mistake. > > Reject both while the write pointer lock is held, since the state has to > be read and acted on atomically. check_zoned_request() in virtio-blk > refuses an append to a conventional zone, so that case needs a caller > that goes to the driver directly, but nothing there examines whether a > zone is full, so a guest can reach the misdirected write. > > Fixes: 4751d09adcc3 ("block: introduce zone append write for zoned devices") > Signed-off-by: Niklas Cassel Looks good, modulo the comment below that needs to be addressed. With that fixed, feel free to add: Reviewed-by: Damien Le Moal > diff --git a/block/io.c b/block/io.c > index b59c7fdf3e..452254bc63 100644 > --- a/block/io.c > +++ b/block/io.c > @@ -3378,6 +3378,15 @@ uint32_t bdrv_zone_index(BlockDriverState *bs, uint64_t offset) > return offset >> ctz64(bs->bl.zone_size); > } > > +bool bdrv_zone_is_full(BlockDriverState *bs, uint32_t index) > +{ > + uint64_t zone_end = MIN((uint64_t)(index + 1) * bs->bl.zone_size, I think this should look at zone capacity, not size. For cases where we have zone cap < zone size, zone full condition is reached when the write pointer is at the zone capacity. > + (uint64_t)bs->total_sectors << BDRV_SECTOR_BITS); > + IO_CODE(); > + > + return bs->wps->wp[index] >= zone_end; > +} -- Damien Le Moal Western Digital Research