Changeset 77949 in vbox for trunk/src/VBox/Additions

Timestamp:

Mar 29, 2019 1:07:19 PM (6 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

129674

Message:

linux/vboxsf: Detect kernel buffers for our iov_iter glue. Seems splice/senfile may use vector functions with kernel address and so may probably other kernel modules. bugref:9172

File:

• trunk/src/VBox/Additions/linux/sharedfolders/regops.c (modified) (2 diffs)

trunk/src/VBox/Additions/linux/sharedfolders/regops.c

@@ -93 +93 @@
 };
 # ifdef VBOX_STRICT
-#  define VBSF_IOV_ITER_INITIALIZER(a_cSegs, a_pIov, a_fWrite) { 0, a_fWrite, 0, a_cSegs, a_pIov, a_pIov, a_cSegs }
+#  define VBSF_IOV_ITER_INITIALIZER(a_cSegs, a_pIov, a_fWrite) \
+    { vbsf_iov_iter_detect_type(a_pIov, a_cSegs), a_fWrite, 0, a_cSegs, a_pIov, a_pIov, a_cSegs }
 # else
-#  define VBSF_IOV_ITER_INITIALIZER(a_cSegs, a_pIov, a_fWrite) { 0, a_fWrite, 0, a_cSegs, a_pIov }
+#  define VBSF_IOV_ITER_INITIALIZER(a_cSegs, a_pIov, a_fWrite) \
+    { vbsf_iov_iter_detect_type(a_pIov, a_cSegs), a_fWrite, 0, a_cSegs, a_pIov }
 # endif
 # define ITER_KVEC 1
@@ -135 +137 @@
 *********************************************************************************************************************************/
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 16, 0) && LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 19)
+
+/**
+ * Detects the vector type.
+ */
+static int vbsf_iov_iter_detect_type(struct iovec const *paIov, size_t cSegs)
+{
+    /* Check the first segment with a non-zero length. */
+    while (cSegs-- > 0) {
+        if (paIov->iov_len > 0) {
+            if (access_ok(VERIFY_READ, paIov->iov_base, paIov->iov_len))
+                return (uintptr_t)paIov->iov_base >= USER_DS.seg ? ITER_KVEC : 0;
+            AssertMsgFailed(("%p LB %#zx\n", paIov->iov_base, paIov->iov_len));
+            break;
+        }
+        paIov++;
+    }
+    return 0;
+}
+
 
 # undef  iov_iter_count