1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
From cec3ed2550073abbfe0f1f6131c44f90c9d05aa8 Mon Sep 17 00:00:00 2001
From: Tobias Schramm <tobleminer@gmail.com>
Date: Wed, 28 Nov 2018 13:39:29 +0100
Subject: Ensure blob_attr length check does not perform out of bounds reads
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Before there might have been as little as one single byte left which
would result in 3 bytes of blob_attr->id_len being out of bounds.
Acked-by: Yousong Zhou <yszhou4tech@gmail.com>
Signed-off-by: Tobias Schramm <tobleminer@gmail.com>
[line wrapped < 72 chars]
Signed-off-by: Petr Štetiar <ynezz@true.cz>
---
blob.h | 4 ++--
blobmsg.h | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
--- a/blob.h
+++ b/blob.h
@@ -243,7 +243,7 @@ blob_put_u64(struct blob_buf *buf, int i
#define __blob_for_each_attr(pos, attr, rem) \
for (pos = (struct blob_attr *) attr; \
- rem > 0 && (blob_pad_len(pos) <= rem) && \
+ rem >= sizeof(struct blob_attr) && (blob_pad_len(pos) <= rem) && \
(blob_pad_len(pos) >= sizeof(struct blob_attr)); \
rem -= blob_pad_len(pos), pos = blob_next(pos))
@@ -251,7 +251,7 @@ blob_put_u64(struct blob_buf *buf, int i
#define blob_for_each_attr(pos, attr, rem) \
for (rem = attr ? blob_len(attr) : 0, \
pos = (struct blob_attr *) (attr ? blob_data(attr) : NULL); \
- rem > 0 && (blob_pad_len(pos) <= rem) && \
+ rem >= sizeof(struct blob_attr) && (blob_pad_len(pos) <= rem) && \
(blob_pad_len(pos) >= sizeof(struct blob_attr)); \
rem -= blob_pad_len(pos), pos = blob_next(pos))
--- a/blobmsg.h
+++ b/blobmsg.h
@@ -266,7 +266,7 @@ int blobmsg_printf(struct blob_buf *buf,
#define blobmsg_for_each_attr(pos, attr, rem) \
for (rem = attr ? blobmsg_data_len(attr) : 0, \
pos = (struct blob_attr *) (attr ? blobmsg_data(attr) : NULL); \
- rem > 0 && (blob_pad_len(pos) <= rem) && \
+ rem >= sizeof(struct blob_attr) && (blob_pad_len(pos) <= rem) && \
(blob_pad_len(pos) >= sizeof(struct blob_attr)); \
rem -= blob_pad_len(pos), pos = blob_next(pos))
|
