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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
From a8bc90052f18348718412cebf7b569da95bad264 Mon Sep 17 00:00:00 2001
From: Ben Hutchings <ben@decadent.org.uk>
Date: Sun, 1 Nov 2015 16:22:53 +0000
Subject: [PATCH 2/2] ppp, slip: Validate VJ compression slot parameters
completely
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Currently slhc_init() treats out-of-range values of rslots and tslots
as equivalent to 0, except that if tslots is too large it will
dereference a null pointer (CVE-2015-7799).
Add a range-check at the top of the function and make it return an
ERR_PTR() on error instead of NULL. Change the callers accordingly.
Compile-tested only.
Reported-by: 郭永刚 <guoyonggang@360.cn>
References: http://article.gmane.org/gmane.comp.security.oss.general/17908
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/isdn/i4l/isdn_ppp.c | 10 ++++------
drivers/net/ppp/ppp_generic.c | 6 ++----
drivers/net/slip/slhc.c | 12 ++++++++----
drivers/net/slip/slip.c | 2 +-
4 files changed, 15 insertions(+), 15 deletions(-)
diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c
index 86f9abebcb72..9c1e8adaf4fc 100644
--- a/drivers/isdn/i4l/isdn_ppp.c
+++ b/drivers/isdn/i4l/isdn_ppp.c
@@ -322,9 +322,9 @@ isdn_ppp_open(int min, struct file *file)
* VJ header compression init
*/
is->slcomp = slhc_init(16, 16); /* not necessary for 2. link in bundle */
- if (!is->slcomp) {
+ if (IS_ERR(is->slcomp)) {
isdn_ppp_ccp_reset_free(is);
- return -ENOMEM;
+ return PTR_ERR(is->slcomp);
}
#endif
#ifdef CONFIG_IPPP_FILTER
@@ -573,10 +573,8 @@ isdn_ppp_ioctl(int min, struct file *file, unsigned int cmd, unsigned long arg)
is->maxcid = val;
#ifdef CONFIG_ISDN_PPP_VJ
sltmp = slhc_init(16, val);
- if (!sltmp) {
- printk(KERN_ERR "ippp, can't realloc slhc struct\n");
- return -ENOMEM;
- }
+ if (IS_ERR(sltmp))
+ return PTR_ERR(sltmp);
if (is->slcomp)
slhc_free(is->slcomp);
is->slcomp = sltmp;
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index ed00446759b2..9a863c6a6a33 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -721,10 +721,8 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
val &= 0xffff;
}
vj = slhc_init(val2+1, val+1);
- if (!vj) {
- netdev_err(ppp->dev,
- "PPP: no memory (VJ compressor)\n");
- err = -ENOMEM;
+ if (IS_ERR(vj)) {
+ err = PTR_ERR(vj);
break;
}
ppp_lock(ppp);
diff --git a/drivers/net/slip/slhc.c b/drivers/net/slip/slhc.c
index 079f7adfcde5..27ed25252aac 100644
--- a/drivers/net/slip/slhc.c
+++ b/drivers/net/slip/slhc.c
@@ -84,8 +84,9 @@ static long decode(unsigned char **cpp);
static unsigned char * put16(unsigned char *cp, unsigned short x);
static unsigned short pull16(unsigned char **cpp);
-/* Initialize compression data structure
+/* Allocate compression data structure
* slots must be in range 0 to 255 (zero meaning no compression)
+ * Returns pointer to structure or ERR_PTR() on error.
*/
struct slcompress *
slhc_init(int rslots, int tslots)
@@ -94,11 +95,14 @@ slhc_init(int rslots, int tslots)
register struct cstate *ts;
struct slcompress *comp;
+ if (rslots < 0 || rslots > 255 || tslots < 0 || tslots > 255)
+ return ERR_PTR(-EINVAL);
+
comp = kzalloc(sizeof(struct slcompress), GFP_KERNEL);
if (! comp)
goto out_fail;
- if ( rslots > 0 && rslots < 256 ) {
+ if (rslots > 0) {
size_t rsize = rslots * sizeof(struct cstate);
comp->rstate = kzalloc(rsize, GFP_KERNEL);
if (! comp->rstate)
@@ -106,7 +110,7 @@ slhc_init(int rslots, int tslots)
comp->rslot_limit = rslots - 1;
}
- if ( tslots > 0 && tslots < 256 ) {
+ if (tslots > 0) {
size_t tsize = tslots * sizeof(struct cstate);
comp->tstate = kzalloc(tsize, GFP_KERNEL);
if (! comp->tstate)
@@ -141,7 +145,7 @@ out_free2:
out_free:
kfree(comp);
out_fail:
- return NULL;
+ return ERR_PTR(-ENOMEM);
}
diff --git a/drivers/net/slip/slip.c b/drivers/net/slip/slip.c
index 05387b1e2e95..a17d86a57734 100644
--- a/drivers/net/slip/slip.c
+++ b/drivers/net/slip/slip.c
@@ -164,7 +164,7 @@ static int sl_alloc_bufs(struct slip *sl, int mtu)
if (cbuff == NULL)
goto err_exit;
slcomp = slhc_init(16, 16);
- if (slcomp == NULL)
+ if (IS_ERR(slcomp))
goto err_exit;
#endif
spin_lock_bh(&sl->lock);
--
2.4.3
|
