4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Geert Uytterhoeven <geert+rene...@glider.be>

commit d2ffed5185df9d8d9ccd150e4340e3b6f96a8381 upstream.

When printing the driver_override parameter when it is 4095 and 4094
bytes long, the printing code would access invalid memory because we
need count + 1 bytes for printing.

Cfr. commits 4efe874aace57dba ("PCI: Don't read past the end of sysfs
"driver_override" buffer") and bf563b01c2895a4b ("driver core: platform:
Don't read past the end of "driver_override" buffer").

Fixes: 3cf385713460eb2b ("ARM: 8256/1: driver coamba: add device binding path 
'driver_override'")
Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be>
Reviewed-by: Todd Kjos <tk...@google.com>
Cc: stable <sta...@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/amba/bus.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -83,7 +83,8 @@ static ssize_t driver_override_store(str
        struct amba_device *dev = to_amba_device(_dev);
        char *driver_override, *old, *cp;
 
-       if (count > PATH_MAX)
+       /* We need to keep extra room for a newline */
+       if (count >= (PAGE_SIZE - 1))
                return -EINVAL;
 
        driver_override = kstrndup(buf, count, GFP_KERNEL);


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