X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Finclude%2Frdma%2Fib.h;fp=kernel%2Finclude%2Frdma%2Fib.h;h=a6b93706b0fc96494d7de3d7408c26fb57436a02;hb=52f993b8e89487ec9ee15a7fb4979e0f09a45b27;hp=cf8f9e700e48939b7633a97df7f815486e0fb8a8;hpb=c189ccac5702322ed843fe17057035b7222a59b6;p=kvmfornfv.git

diff --git a/kernel/include/rdma/ib.h b/kernel/include/rdma/ib.h
index cf8f9e700..a6b93706b 100644
--- a/kernel/include/rdma/ib.h
+++ b/kernel/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 */