[PATCH] RDMA/uverbs: Consider capability of the process that opens the file

[Parav Pandit]

Currently, the capability check is done on the current process which
may have the CAP_NET_RAW capability, but such process may not have
opened the file. A file may could have been opened by a lesser
privilege process that does not possess the CAP_NET_RAW capability.

To avoid such situations, perform the capability checks against
the file's credentials. This approach ensures that the capabilities
of the process that opened the file are enforced.

Fixes: c938a616aadb ("IB/core: Add raw packet QP type")
Signed-off-by: Parav Pandit <parav at nvidia.com>
Suggested-by: Eric W. Biederman <ebiederm at xmission.com>

---

Eric,

Shouldn't we check the capabilities of the process that opened the
file and also the current process that is issuing the create_flow()
ioctl? This way, the minimum capabilities of both processes are
considered.

---
 drivers/infiniband/core/uverbs_cmd.c  | 2 +-
 drivers/infiniband/core/uverbs_main.c | 2 +-
 include/rdma/uverbs_types.h           | 1 +
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 96d639e1ffa0..e028454bcd7e 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -3217,7 +3217,7 @@ static int ib_uverbs_ex_create_flow(struct uverbs_attr_bundle *attrs)
 	if (cmd.comp_mask)
 		return -EINVAL;
 
-	if (!capable(CAP_NET_RAW))
+	if (!file_ns_capable(attrs->ufile->filp, &init_user_ns, CAP_NET_RAW))
 		return -EPERM;
 
 	if (cmd.flow_attr.flags >= IB_FLOW_ATTR_FLAGS_RESERVED)
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 973fe2c7ef53..8e5ee702e9f8 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -993,7 +993,7 @@ static int ib_uverbs_open(struct inode *inode, struct file *filp)
 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
 
 	setup_ufile_idr_uobject(file);
-
+	file->filp = filp;
 	return stream_open(inode, filp);
 
 err_module:
diff --git a/include/rdma/uverbs_types.h b/include/rdma/uverbs_types.h
index 26ba919ac245..06f57d28d349 100644
--- a/include/rdma/uverbs_types.h
+++ b/include/rdma/uverbs_types.h
@@ -181,6 +181,7 @@ struct ib_uverbs_file {
 	struct xarray		idr;
 
 	struct mutex disassociation_lock;
+	struct file *filp;
 };
 
 extern const struct uverbs_obj_type_class uverbs_idr_class;
-- 
2.26.2