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 D1BA62144C3; Tue, 12 Nov 2024 10:48:00 +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=1731408480; cv=none; b=K27bstA+x0eNXY9pqV3tZxd7s0etmQAOkfIg4UhZT5O4kF26rlVrHZa9H+nUyx/DFfEWaSToCR3QI++gPifokwDD9QohtjA3paW5H2MQuU6kDPrMrwJ/CRiSseXioMYrj9k6L3zMhPkDjEZ+4jLMHJMAiIL96xhRycUQx5Crd1o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731408480; c=relaxed/simple; bh=eWlcfspPV1VOk9oGm/kLOhJf5vVeZwQcxo+gkLzeiAE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OMN5WVMsynkoxJxlEmqsq0RKsUk3QxMseZEO12Couamp5aax0NPxMAs46uI9zLFiY6QDH/v0D1AgN0ISDm+GG5yDExwaVLMCnzcolthkm7jbI4uPGGCeNU9KofS1MqEflMuuDUznyshPaEJERGSk3+WB5NKlrlF/yBQuzwpzbEU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZFT+dRyd; 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="ZFT+dRyd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 42534C4CECD; Tue, 12 Nov 2024 10:48:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1731408480; bh=eWlcfspPV1VOk9oGm/kLOhJf5vVeZwQcxo+gkLzeiAE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZFT+dRydIhlfjBHKgwtJb8z8l/Mq6LmYUPfS9bC+1rY5N/S4ZIzN1gk3iQZRZkUh6 l56vGB43cW0XzjEHt98mCpvruLoHhFK4rnlApwQol1/1aCS6PFWluKm00kRnfPdgV4 q08JYEGnobh/CTl0tPgsKsoWxOOBy/2yUNK+2RXo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christoph Hellwig , John Garry , Jens Axboe , Sasha Levin Subject: [PATCH 6.11 176/184] block: fix queue limits checks in blk_rq_map_user_bvec for real Date: Tue, 12 Nov 2024 11:22:14 +0100 Message-ID: <20241112101907.617772721@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241112101900.865487674@linuxfoundation.org> References: <20241112101900.865487674@linuxfoundation.org> User-Agent: quilt/0.67 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 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christoph Hellwig [ Upstream commit be0e822bb3f5259c7f9424ba97e8175211288813 ] blk_rq_map_user_bvec currently only has ad-hoc checks for queue limits, and the last fix to it enabled valid NVMe I/O to pass, but also allowed invalid one for drivers that set a max_segment_size or seg_boundary limit. Fix it once for all by using the bio_split_rw_at helper from the I/O path that indicates if and where a bio would be have to be split to adhere to the queue limits, and it returns a positive value, turn that into -EREMOTEIO to retry using the copy path. Fixes: 2ff949441802 ("block: fix sanity checks in blk_rq_map_user_bvec") Signed-off-by: Christoph Hellwig Reviewed-by: John Garry Link: https://lore.kernel.org/r/20241028090840.446180-1-hch@lst.de Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-map.c | 56 +++++++++++++++---------------------------------- 1 file changed, 17 insertions(+), 39 deletions(-) diff --git a/block/blk-map.c b/block/blk-map.c index 6ef2ec1f7d78b..b5fd1d8574615 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -561,55 +561,33 @@ EXPORT_SYMBOL(blk_rq_append_bio); /* Prepare bio for passthrough IO given ITER_BVEC iter */ static int blk_rq_map_user_bvec(struct request *rq, const struct iov_iter *iter) { - struct request_queue *q = rq->q; - size_t nr_iter = iov_iter_count(iter); - size_t nr_segs = iter->nr_segs; - struct bio_vec *bvecs, *bvprvp = NULL; - const struct queue_limits *lim = &q->limits; - unsigned int nsegs = 0, bytes = 0; + const struct queue_limits *lim = &rq->q->limits; + unsigned int max_bytes = lim->max_hw_sectors << SECTOR_SHIFT; + unsigned int nsegs; struct bio *bio; - size_t i; + int ret; - if (!nr_iter || (nr_iter >> SECTOR_SHIFT) > queue_max_hw_sectors(q)) - return -EINVAL; - if (nr_segs > queue_max_segments(q)) + if (!iov_iter_count(iter) || iov_iter_count(iter) > max_bytes) return -EINVAL; - /* no iovecs to alloc, as we already have a BVEC iterator */ + /* reuse the bvecs from the iterator instead of allocating new ones */ bio = blk_rq_map_bio_alloc(rq, 0, GFP_KERNEL); - if (bio == NULL) + if (!bio) return -ENOMEM; - bio_iov_bvec_set(bio, (struct iov_iter *)iter); - blk_rq_bio_prep(rq, bio, nr_segs); - - /* loop to perform a bunch of sanity checks */ - bvecs = (struct bio_vec *)iter->bvec; - for (i = 0; i < nr_segs; i++) { - struct bio_vec *bv = &bvecs[i]; - - /* - * If the queue doesn't support SG gaps and adding this - * offset would create a gap, fallback to copy. - */ - if (bvprvp && bvec_gap_to_prev(lim, bvprvp, bv->bv_offset)) { - blk_mq_map_bio_put(bio); - return -EREMOTEIO; - } - /* check full condition */ - if (nsegs >= nr_segs || bytes > UINT_MAX - bv->bv_len) - goto put_bio; - if (bytes + bv->bv_len > nr_iter) - break; - nsegs++; - bytes += bv->bv_len; - bvprvp = bv; + /* check that the data layout matches the hardware restrictions */ + ret = bio_split_rw_at(bio, lim, &nsegs, max_bytes); + if (ret) { + /* if we would have to split the bio, copy instead */ + if (ret > 0) + ret = -EREMOTEIO; + blk_mq_map_bio_put(bio); + return ret; } + + blk_rq_bio_prep(rq, bio, nsegs); return 0; -put_bio: - blk_mq_map_bio_put(bio); - return -EINVAL; } /** -- 2.43.0