From 446df5eed4bac7810090ce83a9f16da7d0c55967 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 10 Apr 2018 15:21:45 +0200 Subject: [PATCH] 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 a76c1a73fc671ecf ("PCI: Don't read past the end of sysfs "driver_override" buffer") and 9afe29649e9a608f ("driver core: platform: Don't read past the end of "driver_override" buffer"). Fixes: 169487d3392c21f5 ("ARM: 8256/1: driver coamba: add device binding path 'driver_override'") Signed-off-by: Geert Uytterhoeven Reviewed-by: Todd Kjos Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/amba/bus.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index c77eb6e656462..8e6ac30316624 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); -- 2.39.5