of: Fix crash if an earlycon driver is not found
__earlycon_of_table_sentinel.compatible is a char[128], not a pointer, so
it will never be NULL. Checking it against NULL causes the match loop to
run past the end of the array, and eventually match a bogus entry, under
the following conditions:
- Kernel command line specifies "earlycon" with no parameters
- DT has a stdout-path pointing to a UART node
- The UART driver doesn't use OF_EARLYCON_DECLARE (or maybe the console
driver is compiled out)
Fix this by checking to see if match->compatible is a non-empty string.
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: <stable@vger.kernel.org> # 3.16+
Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index d1ffca8..30e97bc 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -773,7 +773,7 @@
if (offset < 0)
return -ENODEV;
- while (match->compatible) {
+ while (match->compatible[0]) {
unsigned long addr;
if (fdt_node_check_compatible(fdt, offset, match->compatible)) {
match++;