linux-kernel - [PATCH 1/2] habanalabs: use default structure for user input in Debug IOCTL

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190806073743.31575-1-oshpigelman@habana.ai>
Date:   Tue, 6 Aug 2019 07:37:59 +0000
From:   Omer Shpigelman <oshpigelman@...ana.ai>
To:     "oded.gabbay@...il.com" <oded.gabbay@...il.com>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: [PATCH 1/2] habanalabs: use default structure for user input in Debug
 IOCTL

This patch fixes a possible kernel crash when a user provides a too small
input structure to the Debug IOCTL.
The fix sets a default input structure and copies to it the user data.
In case the user provided as input a too small structure, the code will
use the default values taken from the default structure.
Note that in contrary to the input structure, the user can provide an
output structure with changing size or no size at all. Therefore the user
output structure validation is already done in the Debug logic later on.

Signed-off-by: Omer Shpigelman <oshpigelman@...ana.ai>
---
 drivers/misc/habanalabs/habanalabs_ioctl.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/misc/habanalabs/habanalabs_ioctl.c b/drivers/misc/habanalabs/habanalabs_ioctl.c
index ce0cd93a8421..3ce65459b01c 100644
--- a/drivers/misc/habanalabs/habanalabs_ioctl.c
+++ b/drivers/misc/habanalabs/habanalabs_ioctl.c
@@ -144,13 +144,16 @@ static int debug_coresight(struct hl_device *hdev, struct hl_debug_args *args)
 	params->op = args->op;
 
 	if (args->input_ptr && args->input_size) {
-		input = memdup_user(u64_to_user_ptr(args->input_ptr),
-					args->input_size);
-		if (IS_ERR(input)) {
-			rc = PTR_ERR(input);
-			input = NULL;
-			dev_err(hdev->dev,
-				"error %d when copying input debug data\n", rc);
+		input = kzalloc(hl_debug_struct_size[args->op], GFP_KERNEL);
+		if (!input) {
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		if (copy_from_user(input, u64_to_user_ptr(args->input_ptr),
+					args->input_size)) {
+			rc = -EFAULT;
+			dev_err(hdev->dev, "failed to copy input debug data\n");
 			goto out;
 		}
 
-- 
2.17.1