Bug Summary

File:builds/wireshark/wireshark/epan/tvbuff_base64.c
Warning:line 212, column 9
Potential leak of memory pointed to by 'data'

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name tvbuff_base64.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -fno-delete-null-pointer-checks -mframe-pointer=all -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -ffloat16-excess-precision=fast -fbfloat16-excess-precision=fast -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/builds/wireshark/wireshark/build -fcoverage-compilation-dir=/builds/wireshark/wireshark/build -resource-dir /usr/lib/llvm-18/lib/clang/18 -isystem /usr/include/glib-2.0 -isystem /usr/lib/x86_64-linux-gnu/glib-2.0/include -isystem /builds/wireshark/wireshark/epan -isystem /builds/wireshark/wireshark/build/epan -isystem /usr/include/libxml2 -isystem /usr/include/lua5.4 -D G_DISABLE_DEPRECATED -D G_DISABLE_SINGLE_INCLUDES -D WS_BUILD_DLL -D WS_DEBUG -D WS_DEBUG_UTF_8 -D epan_EXPORTS -I /builds/wireshark/wireshark/build -I /builds/wireshark/wireshark -I /builds/wireshark/wireshark/include -I /builds/wireshark/wireshark/wiretap -D _GLIBCXX_ASSERTIONS -internal-isystem /usr/lib/llvm-18/lib/clang/18/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/builds/wireshark/wireshark/= -fmacro-prefix-map=/builds/wireshark/wireshark/build/= -fmacro-prefix-map=../= -Wno-format-truncation -Wno-format-nonliteral -Wno-pointer-sign -std=gnu11 -ferror-limit 19 -fvisibility=hidden -fwrapv -fstrict-flex-arrays=3 -stack-protector 2 -fstack-clash-protection -fcf-protection=full -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -fexceptions -fcolor-diagnostics -analyzer-output=html -dwarf-debug-flags /usr/lib/llvm-18/bin/clang -### --analyze -x c -D G_DISABLE_DEPRECATED -D G_DISABLE_SINGLE_INCLUDES -D WS_BUILD_DLL -D WS_DEBUG -D WS_DEBUG_UTF_8 -D epan_EXPORTS -I /builds/wireshark/wireshark/build -I /builds/wireshark/wireshark -I /builds/wireshark/wireshark/include -I /builds/wireshark/wireshark/wiretap -isystem /usr/include/glib-2.0 -isystem /usr/lib/x86_64-linux-gnu/glib-2.0/include -isystem /builds/wireshark/wireshark/epan -isystem /builds/wireshark/wireshark/build/epan -isystem /usr/include/libxml2 -isystem /usr/include/lua5.4 -fvisibility=hidden -fexcess-precision=fast -fstrict-flex-arrays=3 -fstack-clash-protection -fcf-protection=full -D _GLIBCXX_ASSERTIONS -fstack-protector-strong -fno-delete-null-pointer-checks -fno-strict-overflow -fno-strict-aliasing -fexceptions -Wno-format-truncation -Wno-format-nonliteral -fdiagnostics-color=always -Wno-pointer-sign -fmacro-prefix-map=/builds/wireshark/wireshark/= -fmacro-prefix-map=/builds/wireshark/wireshark/build/= -fmacro-prefix-map=../= -std=gnu11 -fPIC /builds/wireshark/wireshark/epan/tvbuff_base64.c -o /builds/wireshark/wireshark/sbout/2024-12-01-100254-3912-1 -Xclang -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /builds/wireshark/wireshark/sbout/2024-12-01-100254-3912-1 -x c /builds/wireshark/wireshark/epan/tvbuff_base64.c
1/* tvbuff_base64.c
2 * Base-64 tvbuff implementation (based on real tvb)
3 *
4 * Wireshark - Network traffic analyzer
5 * By Gerald Combs <[email protected]>
6 * Copyright 1998 Gerald Combs
7 *
8 * SPDX-License-Identifier: GPL-2.0-or-later
9 */
10
11#include "config.h"
12
13#include <glib.h>
14
15#include <epan/tvbuff.h>
16#include "proto.h"
17
18/* Copy of glib function modified for base64uri */
19
20static const unsigned char mime_base64uri_rank[256] = {
21 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
22 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
23 255,255,255,255,255,255,255,255,255,255,255, 255,255,63,255,255,
24 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255, 0,255,255,
25 255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
26 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,255,255,255,255, 63,
27 255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
28 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,255,255,255,255,255,
29 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
30 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
31 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
32 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
33 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
34 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
35 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
36 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
37};
38 /**
39 * Copy of glib function modified for base64uri
40 * g_base64uri_decode_step: (skip)
41 * @in: (array length=len) (element-type uint8_t): binary input data
42 * @len: max length of @in data to decode
43 * @out: (out caller-allocates) (array) (element-type uint8_t): output buffer
44 * @state: (inout): Saved state between steps, initialize to 0
45 * @save: (inout): Saved state between steps, initialize to 0
46 *
47 * Incrementally decode a sequence of binary data from its Base-64 stringified
48 * representation. By calling this function multiple times you can convert
49 * data in chunks to avoid having to have the full encoded data in memory.
50 *
51 * The output buffer must be large enough to fit all the data that will
52 * be written to it. Since base64 encodes 3 bytes in 4 chars you need
53 * at least: (@len / 4) * 3 + 3 bytes (+ 3 may be needed in case of non-zero
54 * state).
55 *
56 * Returns: The number of bytes of output that was written
57 *
58 * Since: 2.12
59 **/
60static size_t
61g_base64uri_decode_step(const char* in,
62 size_t len,
63 unsigned char* out,
64 int* state,
65 unsigned* save)
66{
67 const unsigned char* inptr;
68 unsigned char* outptr;
69 const unsigned char* inend;
70 unsigned char c, rank;
71 unsigned char last[2];
72 unsigned int v;
73 int i;
74
75 g_return_val_if_fail(in != NULL || len == 0, 0)do { if ((in != ((void*)0) || len == 0)) { } else { g_return_if_fail_warning
(((gchar*) 0), ((const char*) (__func__)), "in != NULL || len == 0"
); return (0); } } while (0);
9
←
Loop condition is false. Exiting loop
→
76 g_return_val_if_fail(out != NULL, 0)do { if ((out != ((void*)0))) { } else { g_return_if_fail_warning
(((gchar*) 0), ((const char*) (__func__)), "out != NULL"); return
(0); } } while (0);
10
←
Assuming 'out' is not equal to null
→
11
←
Taking true branch
→
12
←
Loop condition is false. Exiting loop
→
77 g_return_val_if_fail(state != NULL, 0)do { if ((state != ((void*)0))) { } else { g_return_if_fail_warning
(((gchar*) 0), ((const char*) (__func__)), "state != NULL");
return (0); } } while (0);
13
←
Taking true branch
→
14
←
Loop condition is false. Exiting loop
→
78 g_return_val_if_fail(save != NULL, 0)do { if ((save != ((void*)0))) { } else { g_return_if_fail_warning
(((gchar*) 0), ((const char*) (__func__)), "save != NULL"); return
(0); } } while (0);
15
←
Taking true branch
→
16
←
Loop condition is false. Exiting loop
→
79
80 if (len == 0)
17
←
Assuming 'len' is equal to 0
→
18
←
Taking true branch
→
81 return 0;
82
83 inend = (const unsigned char*)in + len;
84 outptr = out;
85
86 /* convert 4 base64 bytes to 3 normal bytes */
87 v = *save;
88 i = *state;
89
90 last[0] = last[1] = 0;
91
92 /* we use the sign in the state to determine if we got a padding character
93 in the previous sequence */
94 if (i < 0)
95 {
96 i = -i;
97 last[0] = '=';
98 }
99
100 inptr = (const unsigned char*)in;
101 while (inptr < inend)
102 {
103 c = *inptr++;
104 rank = mime_base64uri_rank[c];
105 if (rank != 0xff)
106 {
107 last[1] = last[0];
108 last[0] = c;
109 v = (v << 6) | rank;
110 i++;
111 if (i == 4)
112 {
113 *outptr++ = v >> 16;
114 if (last[1] != '=')
115 *outptr++ = v >> 8;
116 if (last[0] != '=')
117 *outptr++ = v;
118 i = 0;
119 }
120 }
121 }
122
123 *save = v;
124 *state = last[0] == '=' ? -i : i;
125
126 return outptr - out;
127}
128 /**
129 * Copy of glib function modified for base64uri
130 * g_base64uri_decode:
131 * @text: (not nullable): zero-terminated string with base64 text to decode
132 * @out_len: (out): The length of the decoded data is written here
133 *
134 * Decode a sequence of Base-64 encoded text into binary data. Note
135 * that the returned binary data is not necessarily zero-terminated,
136 * so it should not be used as a character string.
137 *
138 * Returns: (transfer full) (array length=out_len) (element-type uint8_t):
139 * newly allocated buffer containing the binary data
140 * that @text represents. The returned buffer must
141 * be freed with g_free().
142 *
143 * Since: 2.12
144 */
145static unsigned char*
146g_base64uri_decode(const char* text,
147 size_t* out_len)
148{
149 unsigned char* ret;
150 size_t input_length;
151 int state = 0;
152 unsigned save = 0;
153
154 g_return_val_if_fail(text != NULL, NULL)do { if ((text != ((void*)0))) { } else { g_return_if_fail_warning
(((gchar*) 0), ((const char*) (__func__)), "text != NULL"); return
(((void*)0)); } } while (0);
2
←
Assuming 'text' is not equal to null
→
3
←
Taking true branch
→
4
←
Loop condition is false. Exiting loop
→
155 g_return_val_if_fail(out_len != NULL, NULL)do { if ((out_len != ((void*)0))) { } else { g_return_if_fail_warning
(((gchar*) 0), ((const char*) (__func__)), "out_len != NULL"
); return (((void*)0)); } } while (0);
5
←
Taking true branch
→
6
←
Loop condition is false. Exiting loop
→
156
157 input_length = strlen(text);
158
159 /* We can use a smaller limit here, since we know the saved state is 0,
160 +1 used to avoid calling g_malloc0(0), and hence returning NULL */
161 ret = (unsigned char * )g_malloc0((input_length / 4) * 3 + 1);
7
←
Memory is allocated
→
162
163 *out_len = g_base64uri_decode_step(text, input_length, ret, &state, &save);
8
←
Calling 'g_base64uri_decode_step'
→
19
←
Returning from 'g_base64uri_decode_step'
→
164
165 return ret;
166}
167
168tvbuff_t *
169base64_to_tvb(tvbuff_t *parent, const char *base64)
170{
171 tvbuff_t *tvb;
172 char *data;
173 size_t len;
174
175 data = g_base64_decode(base64, &len);
176 tvb = tvb_new_child_real_data(parent, (const uint8_t *)data, (int)len, (int)len);
177
178 tvb_set_free_cb(tvb, g_free);
179
180 return tvb;
181}
182
183tvbuff_t*
184base64_tvb_to_new_tvb(tvbuff_t* parent, int offset, int length)
185{
186 tvbuff_t* tvb;
187 char* data, *tmp;
188 size_t len;
189
190 tmp = tvb_get_string_enc(NULL((void*)0), parent, offset, length, ENC_ASCII0x00000000);
191 data = g_base64_decode(tmp, &len);
192 wmem_free(NULL((void*)0), tmp);
193
194 tvb = tvb_new_child_real_data(parent, (const uint8_t*)data, (int)len, (int)len);
195
196 tvb_set_free_cb(tvb, g_free);
197
198 return tvb;
199}
200
201tvbuff_t*
202base64uri_tvb_to_new_tvb(tvbuff_t* parent, int offset, int length)
203{
204 tvbuff_t* tvb;
205 char* data, *tmp;
206 size_t len = 0;
207
208 tmp = tvb_get_string_enc(NULL((void*)0), parent, offset, length, ENC_ASCII0x00000000);
209 data = g_base64uri_decode(tmp, &len);
1
Calling 'g_base64uri_decode'
→
20
←
Returned allocated memory
→
210 wmem_free(NULL((void*)0), tmp);
211
212 tvb = tvb_new_child_real_data(parent, (const uint8_t*)data, (int)len, (int)len);
21
←
Potential leak of memory pointed to by 'data'
213
214 tvb_set_free_cb(tvb, g_free);
215
216 return tvb;
217}
218/*
219 * Editor modelines - https://www.wireshark.org/tools/modelines.html
220 *
221 * Local Variables:
222 * c-basic-offset: 2
223 * tab-width: 8
224 * indent-tabs-mode: nil
225 * End:
226 *
227 * ex: set shiftwidth=2 tabstop=8 expandtab:
228 * :indentSize=2:tabSize=8:noTabs=true:
229 */