IOMUX: Fix access past end of console_devices

We should only access console_devices[file][i] once we have checked that i
< cd_count[file]. Otherwise, we will access uninitialized memory at the end
of the loop. console_devices[file][i] should not be NULL, but putting the
assignment in the loop condition allows us to ensure that i is checked
beforehand. This isn't a bug, but it does make valgrind stop complaining.

Fixes: 400797cad3 ("IOMUX: Split out for_each_console_dev() helper macro")
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Andrew Scull <ascull@google.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

diff --git a/include/iomux.h b/include/iomux.h
index 37f5f6dee69f290be338122921ea63044af1ca01..35caa697ebff58dff3286d19ba41a90ef7818961 100644 (file)
--- a/include/iomux.h
+++ b/include/iomux.h
@@ -24,10 +24,10 @@ extern struct stdio_dev **console_devices[MAX_FILES];
  */
 extern int cd_count[MAX_FILES];
 
-#define for_each_console_dev(i, file, dev)             \
-       for (i = 0, dev = console_devices[file][i];     \
-            i < cd_count[file];                        \
-            i++, dev = console_devices[file][i])
+#define for_each_console_dev(i, file, dev)                             \
+       for (i = 0;                                                     \
+            i < cd_count[file] && (dev = console_devices[file][i]);    \
+            i++)
 
 int iomux_match_device(struct stdio_dev **, const int, struct stdio_dev *);
 int iomux_doenv(const int, const char *);