[PATCH v2 04/13] RDMA: Add ib_copy_validate_udata_in_cm()

Jason Gunthorpe
2026-02-27T01:11:24Z

For structures with comp_mask also absorb the check of comp_mask valid
bits into the helper. This is slightly tricky because ~ might not fully
extend to 64 bits, the helper inserts an explicit type to ensure that ~
covers all bits.

Tested-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Acked-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/infiniband/core/uverbs_ioctl.c | 12 ++++++++++++
include/rdma/uverbs_ioctl.h | 25 +++++++++++++++++++++++++
2 files changed, 37 insertions(+)

diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
index 81798c0875ed3a..5e5b00c6236fa8 100644
--- a/drivers/infiniband/core/uverbs_ioctl.c
+++ b/drivers/infiniband/core/uverbs_ioctl.c
@@ -898,3 +898,15 @@ int _ib_copy_validate_udata_in(struct ib_udata *udata, void *req,
return 0;
}
EXPORT_SYMBOL(_ib_copy_validate_udata_in);
+
+int _ib_copy_validate_udata_cm_fail(struct ib_udata *udata, u64 req_cm,
+ u64 valid_cm)
+{
+ ibdev_dbg(
+ rdma_udata_to_dev(udata),
+ "System call driver input udata has unsupported comp_mask %llx & ~%llx = %llx for ioctl %ps called by %pSR\n",
+ req_cm, valid_cm, req_cm & ~valid_cm,
+ uverbs_get_handler_fn(udata), __builtin_return_address(0));
+ return -EOPNOTSUPP;
+}
+EXPORT_SYMBOL(_ib_copy_validate_udata_cm_fail);
diff --git a/include/rdma/uverbs_ioctl.h b/include/rdma/uverbs_ioctl.h
index 5ea53a49b7c6b5..e4719419460422 100644
--- a/include/rdma/uverbs_ioctl.h
+++ b/include/rdma/uverbs_ioctl.h
@@ -1044,4 +1044,29 @@ uverbs_get_raw_fd(int *to, const struct uverbs_attr_bundle *attrs_bundle,
_ib_copy_validate_udata_in(_udata, &(_req), sizeof(_req), \
offsetofend(typeof(_req), _end_member))

+int _ib_copy_validate_udata_cm_fail(struct ib_udata *udata, u64 req_cm,
+ u64 valid_cm);
+
+/**
+ * ib_copy_validate_udata_in_cm - Copy the req structure and check the comp_mask
+ * @_udata: The system calls ib_udata struct
+ * @_req: The name of an on-stack structure that holds the driver data
+ * @_end_member: The member in the struct that is the original end of struct
+ * from the first kernel to introduce it.
+ * @_valid_cm: A bitmask of bits permitted in the comp_mask_field.
+ *
+ * Check that the udata input request struct is properly formed for this kernel.
+ * Then copy it into req
+ */
+#define ib_copy_validate_udata_in_cm(_udata, _req, _end_member, _valid_cm) \
+ ({ \
+ typeof((_req).comp_mask) __valid_cm = _valid_cm; \
+ int ret = \
+ ib_copy_validate_udata_in(_udata, _req, _end_member); \
+ if (!ret && ((_req).comp_mask & ~__valid_cm)) \
+ ret = _ib_copy_validate_udata_cm_fail( \
+ _udata, (_req).comp_mask, __valid_cm); \
+ ret; \
+ })
+
#endif
--
2.43.0