[PATCH 1/2] habanalabs: Validate user address before mapping

[Oded Gabbay]

From: Ofir Bitton <obit...@habana.ai>

User address must be validated before driver performs address map.

Signed-off-by: Ofir Bitton <obit...@habana.ai>
Reviewed-by: Oded Gabbay <oded.gab...@gmail.com>
Signed-off-by: Oded Gabbay <oded.gab...@gmail.com>
---
 drivers/misc/habanalabs/common/command_buffer.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/habanalabs/common/command_buffer.c 
b/drivers/misc/habanalabs/common/command_buffer.c
index 7c38c4f7f9c0..a8004911c977 100644
--- a/drivers/misc/habanalabs/common/command_buffer.c
+++ b/drivers/misc/habanalabs/common/command_buffer.c
@@ -10,6 +10,7 @@
 
 #include <linux/mm.h>
 #include <linux/slab.h>
+#include <linux/uaccess.h>
 #include <linux/genalloc.h>
 
 static void cb_fini(struct hl_device *hdev, struct hl_cb *cb)
@@ -300,7 +301,7 @@ int hl_cb_mmap(struct hl_fpriv *hpriv, struct 
vm_area_struct *vma)
        struct hl_device *hdev = hpriv->hdev;
        struct hl_cb *cb;
        phys_addr_t address;
-       u32 handle;
+       u32 handle, user_cb_size;
        int rc;
 
        handle = vma->vm_pgoff;
@@ -314,7 +315,8 @@ int hl_cb_mmap(struct hl_fpriv *hpriv, struct 
vm_area_struct *vma)
        }
 
        /* Validation check */
-       if ((vma->vm_end - vma->vm_start) != ALIGN(cb->size, PAGE_SIZE)) {
+       user_cb_size = vma->vm_end - vma->vm_start;
+       if (user_cb_size != ALIGN(cb->size, PAGE_SIZE)) {
                dev_err(hdev->dev,
                        "CB mmap failed, mmap size 0x%lx != 0x%x cb size\n",
                        vma->vm_end - vma->vm_start, cb->size);
@@ -322,6 +324,16 @@ int hl_cb_mmap(struct hl_fpriv *hpriv, struct 
vm_area_struct *vma)
                goto put_cb;
        }
 
+       if (!access_ok((void __user *) (uintptr_t) vma->vm_start,
+                                                       user_cb_size)) {
+               dev_err(hdev->dev,
+                       "user pointer is invalid - 0x%lx\n",
+                       vma->vm_start);
+
+               rc = -EINVAL;
+               goto put_cb;
+       }
+
        spin_lock(&cb->lock);
 
        if (cb->mmap) {
-- 
2.17.1