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
|
From: Zephkeks <zephyrofficialdiscord@gmail.com>
Date: Tue, 13 May 2025 11:04:17 +0200
Subject: CVE-2025-46836: interface.c: Stack-based Buffer Overflow in
get_name()
Origin: https://github.com/ecki/net-tools/commit/7a8f42fb20013a1493d8cae1c43436f85e656f2d
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2025-46836
Bug-Debian: https://bugs.debian.org/1105806
Coordinated as GHSA-pfwf-h6m3-63wf
---
lib/interface.c | 63 ++++++++++++++++++++++++++++++-------------------
1 file changed, 39 insertions(+), 24 deletions(-)
diff --git a/lib/interface.c b/lib/interface.c
index 71d4163ac36f..a054f126e2f1 100644
--- a/lib/interface.c
+++ b/lib/interface.c
@@ -211,32 +211,47 @@ out:
}
static const char *get_name(char *name, const char *p)
+/* Safe version — guarantees at most IFNAMSIZ‑1 bytes are copied
+ and the destination buffer is always NUL‑terminated. */
{
- while (isspace(*p))
- p++;
- while (*p) {
- if (isspace(*p))
- break;
- if (*p == ':') { /* could be an alias */
- const char *dot = p++;
- while (*p && isdigit(*p)) p++;
- if (*p == ':') {
- /* Yes it is, backup and copy it. */
- p = dot;
- *name++ = *p++;
- while (*p && isdigit(*p)) {
- *name++ = *p++;
- }
- } else {
- /* No, it isn't */
- p = dot;
- }
- p++;
- break;
- }
- *name++ = *p++;
+ char *dst = name; /* current write ptr */
+ const char *end = name + IFNAMSIZ - 1; /* last byte we may write */
+
+ /* Skip leading white‑space. */
+ while (isspace((unsigned char)*p))
+ ++p;
+
+ /* Copy until white‑space, end of string, or buffer full. */
+ while (*p && !isspace((unsigned char)*p) && dst < end) {
+ if (*p == ':') { /* possible alias veth0:123: */
+ const char *dot = p; /* remember the colon */
+ ++p;
+ while (*p && isdigit((unsigned char)*p))
+ ++p;
+
+ if (*p == ':') { /* confirmed alias */
+ p = dot; /* rewind and copy it all */
+
+ /* copy the colon */
+ if (dst < end)
+ *dst++ = *p++;
+
+ /* copy the digits */
+ while (*p && isdigit((unsigned char)*p) && dst < end)
+ *dst++ = *p++;
+
+ if (*p == ':') /* consume trailing colon */
+ ++p;
+ } else { /* if so treat as normal */
+ p = dot;
+ }
+ break; /* interface name ends here */
+ }
+
+ *dst++ = *p++; /* ordinary character copy */
}
- *name++ = '\0';
+
+ *dst = '\0'; /* always NUL‑terminate */
return p;
}
--
2.49.0
|
