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authorGeert Uytterhoeven <geert+renesas@glider.be>2018-04-10 15:21:45 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-04-25 18:07:17 +0200
commitd2ffed5185df9d8d9ccd150e4340e3b6f96a8381 (patch)
treea3a11243b2bff482034b31415fa485407d2c0ecb
parentARM: amba: Fix race condition with driver_override (diff)
downloadlinux-d2ffed5185df9d8d9ccd150e4340e3b6f96a8381.tar.xz
linux-d2ffed5185df9d8d9ccd150e4340e3b6f96a8381.zip
ARM: amba: Don't read past the end of sysfs "driver_override" buffer
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+renesas@glider.be> Reviewed-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/amba/bus.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index c77eb6e65646..8e6ac3031662 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -87,7 +87,8 @@ static ssize_t driver_override_store(struct device *_dev,
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);