Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma

Pull rdma fixes from Doug Ledford:
 "Final set of -rc fixes for 4.6.

  I've collected up a number of patches that are all pretty small with
  the exception of only a couple.  The hfi1 driver has a number of
  important patches, and it is what really drives the line count of this
  pull request up.  These are all small and I've got this kernel built
  and running in the test lab (I have most of the hardware, I think nes
  is the only thing in this patch set that I can't say I've personally
  tested and have up and running).

  Summary:

   - A number of collected fixes for oopses, memory corruptions,
     deadlocks, etc.  All of these fixes are small (many only 5-10
     lines), obvious, and tested.

   - Fix for the security issue related to the use of write for
     bi-directional communications"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  RDMA/nes: don't leak skb if carrier down
  IB/security: Restrict use of the write() interface
  IB/hfi1: Use kernel default llseek for ui device
  IB/hfi1: Don't attempt to free resources if initialization failed
  IB/hfi1: Fix missing lock/unlock in verbs drain callback
  IB/rdmavt: Fix send scheduling
  IB/hfi1: Prevent unpinning of wrong pages
  IB/hfi1: Fix deadlock caused by locking with wrong scope
  IB/hfi1: Prevent NULL pointer deferences in caching code
  MAINTAINERS: Update iser/isert maintainer contact info
  IB/mlx5: Expose correct max_sge_rd limit
  RDMA/iw_cxgb4: Fix bar2 virt addr calculation for T4 chips
  iw_cxgb4: handle draining an idle qp
  iw_cxgb3: initialize ibdev.iwcm->ifname for port mapping
  iw_cxgb4: initialize ibdev.iwcm->ifname for port mapping
  IB/core: Don't drain non-existent rq queue-pair
  IB/core: Fix oops in ib_cache_gid_set_default_gid

2 files changed, 27 insertions, 0 deletions

diff --git a/include/linux/mlx5/device.h b/include/linux/mlx5/device.h
index 8156e3c9239c..b3575f392492 100644
--- a/include/linux/mlx5/device.h
+++ b/include/linux/mlx5/device.h
@@ -392,6 +392,17 @@ enum {
 	MLX5_CAP_OFF_CMDIF_CSUM		= 46,
 };
 
+enum {
+	/*
+	 * Max wqe size for rdma read is 512 bytes, so this
+	 * limits our max_sge_rd as the wqe needs to fit:
+	 * - ctrl segment (16 bytes)
+	 * - rdma segment (16 bytes)
+	 * - scatter elements (16 bytes each)
+	 */
+	MLX5_MAX_SGE_RD	= (512 - 16 - 16) / 16
+};
+
 struct mlx5_inbox_hdr {
 	__be16		opcode;
 	u8		rsvd[4];
diff --git a/include/rdma/ib.h b/include/rdma/ib.h
index cf8f9e700e48..a6b93706b0fc 100644
--- a/include/rdma/ib.h
+++ b/include/rdma/ib.h
@@ -34,6 +34,7 @@
 #define _RDMA_IB_H
 
 #include <linux/types.h>
+#include <linux/sched.h>
 
 struct ib_addr {
 	union {
@@ -86,4 +87,19 @@ struct sockaddr_ib {
 	__u64			sib_scope_id;
 };
 
+/*
+ * The IB interfaces that use write() as bi-directional ioctl() are
+ * fundamentally unsafe, since there are lots of ways to trigger "write()"
+ * calls from various contexts with elevated privileges. That includes the
+ * traditional suid executable error message writes, but also various kernel
+ * interfaces that can write to file descriptors.
+ *
+ * This function provides protection for the legacy API by restricting the
+ * calling context.
+ */
+static inline bool ib_safe_file_access(struct file *filp)
+{
+	return filp->f_cred == current_cred() && segment_eq(get_fs(), USER_DS);
+}
+
 #endif /* _RDMA_IB_H */