From: Todd Poynor <toddpoynor@google.com>
Date: Sat, 21 Jul 2018 13:34:57 +0000 (-0700)
Subject: staging: gasket: avoid copy to user on error in coherent alloc config
X-Git-Tag: for-linus-20180825~50^2~379
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=5c4a5d3ddd724d1c4f27c3b52ad0980c4c750999;p=linux-2.6-block.git

staging: gasket: avoid copy to user on error in coherent alloc config

gasket_config_coherent_allocator() on error return the error to caller
without copying a possibly-update DMA address back to userspace.

Reported-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/gasket/gasket_ioctl.c b/drivers/staging/gasket/gasket_ioctl.c
index 1b164ac7a049..8cf094b90cdb 100644
--- a/drivers/staging/gasket/gasket_ioctl.c
+++ b/drivers/staging/gasket/gasket_ioctl.c
@@ -441,8 +441,10 @@ static int gasket_config_coherent_allocator(
 			gasket_dev, ibuf.size, &ibuf.dma_address,
 			ibuf.page_table_index);
 	}
+	if (ret)
+		return ret;
 	if (copy_to_user(argp, &ibuf, sizeof(ibuf)))
 		return -EFAULT;
 
-	return ret;
+	return 0;
 }