(count + p) is not checked for integer overflow. If p < fbmemlength and count == (size_t)(1 - p) (very big unsigned integer) then count + p == 1 < fbmemlength and copy_to_user(base_addr+p, buf, count) overflows base_addr. Signed-off-by: Vasiliy Kulikov <segoon@xxxxxxxxxxxx> --- Compile tested only. drivers/video/arcfb.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/video/arcfb.c b/drivers/video/arcfb.c index 3ec4923..67a4cd4 100644 --- a/drivers/video/arcfb.c +++ b/drivers/video/arcfb.c @@ -454,7 +454,7 @@ static ssize_t arcfb_write(struct fb_info *info, const char __user *buf, xres = info->var.xres; fbmemlength = (xres * info->var.yres)/8; - if (p > fbmemlength) + if (p > fbmemlength || (p + count < p)) return -ENOSPC; err = 0; -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
