From 09c9062d4f62199a634a45e2bb9e6e8e572cc78c Mon Sep 17 00:00:00 2001 From: Xixin Liu Date: Thu, 25 Jun 2026 10:00:00 +0800 Subject: [PATCH] nvme: zns: cap zone report nr_zones by DMA buffer size With Partial Report (PR=1), the Number of Zones (NZ) field in the report header must equal the number of zone descriptors fully transferred in the DMA buffer (ZNS Command Set Specification Rev 1.2, section 3.4.2). nvme_ns_report_zones() does not cap the parse loop by max_in_buf derived from buflen. Cap nz with min3() over the device-reported count, nr_zones - zone_idx, and max_in_buf. Signed-off-by: Xixin Liu Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch --- drivers/nvme/host/zns.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/nvme/host/zns.c b/drivers/nvme/host/zns.c index 8ed1b6a33454..03a2528b7192 100644 --- a/drivers/nvme/host/zns.c +++ b/drivers/nvme/host/zns.c @@ -178,7 +178,7 @@ int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector, struct nvme_zone_report *report; struct nvme_command c = { }; int ret, zone_idx = 0; - unsigned int nz, i; + unsigned int max_in_buf, nz, i; size_t buflen; if (ns->head->ids.csi != NVME_CSI_ZNS) @@ -188,6 +188,9 @@ int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector, if (!report) return -ENOMEM; + max_in_buf = (buflen - sizeof(struct nvme_zone_report)) / + sizeof(struct nvme_zone_descriptor); + c.zmr.opcode = nvme_cmd_zone_mgmt_recv; c.zmr.nsid = cpu_to_le32(ns->head->ns_id); c.zmr.numd = cpu_to_le32(nvme_bytes_to_numd(buflen)); @@ -207,7 +210,8 @@ int nvme_ns_report_zones(struct nvme_ns *ns, sector_t sector, goto out_free; } - nz = min((unsigned int)le64_to_cpu(report->nr_zones), nr_zones); + nz = min3((unsigned int)le64_to_cpu(report->nr_zones), + nr_zones - zone_idx, max_in_buf); if (!nz) break;