From e4fbcf32c860f98103ca7f1dc8c0dc69e2219ec6 Mon Sep 17 00:00:00 2001
From: Kanchan Joshi <joshi.k@samsung.com>
Date: Tue, 1 Nov 2022 10:43:07 +0100
Subject: [PATCH] nvme: identify-namespace without CAP_SYS_ADMIN
Allow all identify-namespace variants (CNS 00h, 05h and 08h) without
requiring CAP_SYS_ADMIN. The information (retrieved using id-ns) is
needed to form IO commands for passthrough interface.
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/nvme/host/ioctl.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 1d68f161064ae..9550a69029b36 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -22,9 +22,23 @@ static bool nvme_cmd_allowed(struct nvme_ns *ns, struct nvme_command *c,
c->common.opcode == nvme_fabrics_command)
return false;
- /* do not allow unprivileged admin commands */
- if (!ns)
+ /*
+ * Do not allow unprivileged passthrough of admin commands except
+ * for a subset of identify commands that contain information required
+ * to form proper I/O commands in userspace and do not expose any
+ * potentially sensitive information.
+ */
+ if (!ns) {
+ if (c->common.opcode == nvme_admin_identify) {
+ switch (c->identify.cns) {
+ case NVME_ID_CNS_NS:
+ case NVME_ID_CNS_CS_NS:
+ case NVME_ID_CNS_NS_CS_INDEP:
+ return true;
+ }
+ }
return false;
+ }
/*
* Only allow I/O commands that transfer data to the controller if the
--
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