From f594863967d87b7fcbff6e724d51135fd701a13d Mon Sep 17 00:00:00 2001 From: Guixin Liu Date: Tue, 4 Aug 2026 11:36:05 +0800 Subject: [PATCH] nvmet: fix NULL pointer dereference in nvmet_execute_identify_ns_zns() When a host issues an Identify command with CNS 05h (I/O Command Set specific Identify Namespace) and CSI 02h (ZNS) targeting a file-backed namespace, nvmet_execute_identify_ns_zns() calls bdev_is_zoned() on req->ns->bdev. A file-backed namespace has no block device, so req->ns->bdev is NULL and bdev_is_zoned() dereferences it, oopsing. The I/O command set is selected by the host-supplied CSI field and the command is routed here whenever CONFIG_BLK_DEV_ZONED is enabled, independent of the namespace backing type, so any file-backed namespace is exposed. Reject the command with Invalid Field when the namespace is not backed by a block device. Fixes: aaf2e048af27 ("nvmet: add ZBD over ZNS backend support") Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Signed-off-by: Guixin Liu Signed-off-by: Keith Busch --- drivers/nvme/target/zns.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/nvme/target/zns.c b/drivers/nvme/target/zns.c index f00921931eb6..a13befd5f3ad 100644 --- a/drivers/nvme/target/zns.c +++ b/drivers/nvme/target/zns.c @@ -116,7 +116,7 @@ void nvmet_execute_identify_ns_zns(struct nvmet_req *req) mutex_unlock(&req->ns->subsys->lock); } - if (!bdev_is_zoned(req->ns->bdev)) { + if (!req->ns->bdev || !bdev_is_zoned(req->ns->bdev)) { status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR; req->error_loc = offsetof(struct nvme_identify, nsid); goto out;