Bug Summary

File:build-scan/../src/basic/bus-label.c
Warning:line 71, column 40
Use of zero-allocated memory

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-unknown-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name bus-label.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -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 -mframe-pointer=all -relaxed-aliasing -menable-no-infs -menable-no-nans -menable-unsafe-fp-math -fno-signed-zeros -mreassociate -freciprocal-math -fdenormal-fp-math=preserve-sign,preserve-sign -ffp-contract=fast -fno-rounding-math -ffast-math -ffinite-math-only -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -fno-split-dwarf-inlining -debugger-tuning=gdb -resource-dir /usr/lib64/clang/12.0.0 -include config.h -I src/basic/libbasic.a.p -I src/basic -I ../src/basic -I src/shared -I ../src/shared -I src/systemd -I ../src/systemd -I src/journal -I ../src/journal -I src/journal-remote -I ../src/journal-remote -I src/nspawn -I ../src/nspawn -I src/resolve -I ../src/resolve -I src/timesync -I ../src/timesync -I ../src/time-wait-sync -I src/login -I ../src/login -I src/udev -I ../src/udev -I src/libudev -I ../src/libudev -I src/core -I ../src/core -I ../src/libsystemd/sd-bus -I ../src/libsystemd/sd-device -I ../src/libsystemd/sd-hwdb -I ../src/libsystemd/sd-id128 -I ../src/libsystemd/sd-netlink -I ../src/libsystemd/sd-network -I src/libsystemd-network -I ../src/libsystemd-network -I . -I .. -I /usr/include/blkid -I /usr/include/libmount -D _FILE_OFFSET_BITS=64 -internal-isystem /usr/local/include -internal-isystem /usr/lib64/clang/12.0.0/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -Wwrite-strings -Wno-unused-parameter -Wno-missing-field-initializers -Wno-unused-result -Wno-format-signedness -Wno-error=nonnull -std=gnu99 -fconst-strings -fdebug-compilation-dir /home/mrc0mmand/repos/@redhat-plumbers/systemd-rhel8/build-scan -ferror-limit 19 -fvisibility default -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -analyzer-output=html -faddrsig -o /tmp/scan-build-2021-07-16-221226-1465241-1 -x c ../src/basic/bus-label.c

../src/basic/bus-label.c

→
1/* SPDX-License-Identifier: LGPL-2.1+ */
2
3#include <stdlib.h>
4
5#include "alloc-util.h"
6#include "bus-label.h"
7#include "hexdecoct.h"
8#include "macro.h"
9
10char *bus_label_escape(const char *s) {
11 char *r, *t;
12 const char *f;
13
14 assert_return(s, NULL)do { if (!(((__builtin_expect(!!(s),1))) ? (1) : (log_assert_failed_return_realm
(LOG_REALM_SYSTEMD, ("s"), "../src/basic/bus-label.c", 14, __PRETTY_FUNCTION__
), 0))) return (((void*)0)); } while (0);
15
16 /* Escapes all chars that D-Bus' object path cannot deal
17 * with. Can be reversed with bus_path_unescape(). We special
18 * case the empty string. */
19
20 if (*s == 0)
21 return strdup("_");
22
23 r = new(char, strlen(s)*3 + 1)((char*) malloc_multiply(sizeof(char), (strlen(s)*3 + 1)));
24 if (!r)
25 return NULL((void*)0);
26
27 for (f = s, t = r; *f; f++) {
28
29 /* Escape everything that is not a-zA-Z0-9. We also
30 * escape 0-9 if it's the first character */
31
32 if (!(*f >= 'A' && *f <= 'Z') &&
33 !(*f >= 'a' && *f <= 'z') &&
34 !(f > s && *f >= '0' && *f <= '9')) {
35 *(t++) = '_';
36 *(t++) = hexchar(*f >> 4);
37 *(t++) = hexchar(*f);
38 } else
39 *(t++) = *f;
40 }
41
42 *t = 0;
43
44 return r;
45}
46
47char *bus_label_unescape_n(const char *f, size_t l) {
48 char *r, *t;
49 size_t i;
50
51 assert_return(f, NULL)do { if (!(((__builtin_expect(!!(f),1))) ? (1) : (log_assert_failed_return_realm
(LOG_REALM_SYSTEMD, ("f"), "../src/basic/bus-label.c", 51, __PRETTY_FUNCTION__
), 0))) return (((void*)0)); } while (0);
1
Assuming 'f' is non-null
→
2
←
'?' condition is true
→
3
←
Taking false branch
→
4
←
Loop condition is false. Exiting loop
→
52
53 /* Special case for the empty string */
54 if (l == 1 && *f == '_')
5
←
Assuming 'l' is not equal to 1
→
55 return strdup("");
56
57 r = new(char, l + 1)((char*) malloc_multiply(sizeof(char), (l + 1)));
6
←
Calling 'malloc_multiply'
→
9
←
Returned allocated memory
→
58 if (!r)
10
←
Assuming 'r' is non-null
→
11
←
Taking false branch
→
59 return NULL((void*)0);
60
61 for (i = 0, t = r; i < l; ++i) {
12
←
Loop condition is true. Entering loop body
→
62 if (f[i] == '_') {
13
←
Assuming the condition is true
→
14
←
Taking true branch
→
63 int a, b;
64
65 if (l - i < 3 ||
17
←
Taking false branch
→
66 (a = unhexchar(f[i + 1])) < 0 ||
15
←
Assuming the condition is false
→
67 (b = unhexchar(f[i + 2])) < 0) {
16
←
Assuming the condition is false
→
68 /* Invalid escape code, let's take it literal then */
69 *(t++) = '_';
70 } else {
71 *(t++) = (char) ((a << 4) | b);
18
←
Use of zero-allocated memory
72 i += 2;
73 }
74 } else
75 *(t++) = f[i];
76 }
77
78 *t = 0;
79
80 return r;
81}
←

../src/basic/alloc-util.h

1/* SPDX-License-Identifier: LGPL-2.1+ */
2#pragma once
3
4#include <alloca.h>
5#include <stddef.h>
6#include <stdlib.h>
7#include <string.h>
8
9#include "macro.h"
10
11#define new(t, n)((t*) malloc_multiply(sizeof(t), (n))) ((t*) malloc_multiply(sizeof(t), (n)))
12
13#define new0(t, n)((t*) calloc((n), sizeof(t))) ((t*) calloc((n), sizeof(t)))
14
15#define newa(t, n)({ do { if ((__builtin_expect(!!(!(!size_multiply_overflow(sizeof
(t), n))),0))) log_assert_failed_realm(LOG_REALM_SYSTEMD, ("!size_multiply_overflow(sizeof(t), n)"
), "../src/basic/alloc-util.h", 15, __PRETTY_FUNCTION__); } while
(0); (t*) __builtin_alloca (sizeof(t)*(n)); }) \
16 ({ \
17 assert(!size_multiply_overflow(sizeof(t), n))do { if ((__builtin_expect(!!(!(!size_multiply_overflow(sizeof
(t), n))),0))) log_assert_failed_realm(LOG_REALM_SYSTEMD, ("!size_multiply_overflow(sizeof(t), n)"
), "../src/basic/alloc-util.h", 17, __PRETTY_FUNCTION__); } while
(0); \
18 (t*) alloca(sizeof(t)*(n))__builtin_alloca (sizeof(t)*(n)); \
19 })
20
21#define newa0(t, n)({ do { if ((__builtin_expect(!!(!(!size_multiply_overflow(sizeof
(t), n))),0))) log_assert_failed_realm(LOG_REALM_SYSTEMD, ("!size_multiply_overflow(sizeof(t), n)"
), "../src/basic/alloc-util.h", 21, __PRETTY_FUNCTION__); } while
(0); (t*) ({ char *_new_; size_t _len_ = sizeof(t)*(n); _new_
= __builtin_alloca (_len_); (void *) memset(_new_, 0, _len_)
; }); }) \
22 ({ \
23 assert(!size_multiply_overflow(sizeof(t), n))do { if ((__builtin_expect(!!(!(!size_multiply_overflow(sizeof
(t), n))),0))) log_assert_failed_realm(LOG_REALM_SYSTEMD, ("!size_multiply_overflow(sizeof(t), n)"
), "../src/basic/alloc-util.h", 23, __PRETTY_FUNCTION__); } while
(0); \
24 (t*) alloca0(sizeof(t)*(n))({ char *_new_; size_t _len_ = sizeof(t)*(n); _new_ = __builtin_alloca
(_len_); (void *) memset(_new_, 0, _len_); }); \
25 })
26
27#define newdup(t, p, n)((t*) memdup_multiply(p, sizeof(t), (n))) ((t*) memdup_multiply(p, sizeof(t), (n)))
28
29#define newdup_suffix0(t, p, n)((t*) memdup_suffix0_multiply(p, sizeof(t), (n))) ((t*) memdup_suffix0_multiply(p, sizeof(t), (n)))
30
31#define malloc0(n)(calloc(1, (n))) (calloc(1, (n)))
32
33static inline void *mfree(void *memory) {
34 free(memory);
35 return NULL((void*)0);
36}
37
38#define free_and_replace(a, b)({ free(a); (a) = (b); (b) = ((void*)0); 0; }) \
39 ({ \
40 free(a); \
41 (a) = (b); \
42 (b) = NULL((void*)0); \
43 0; \
44 })
45
46void* memdup(const void *p, size_t l) _alloc_(2);
47void* memdup_suffix0(const void *p, size_t l) _alloc_(2);
48
49static inline void freep(void *p) {
50 free(*(void**) p);
51}
52
53#define _cleanup_free___attribute__((cleanup(freep))) _cleanup_(freep)__attribute__((cleanup(freep)))
54
55static inline bool_Bool size_multiply_overflow(size_t size, size_t need) {
56 return _unlikely_(need != 0 && size > (SIZE_MAX / need))(__builtin_expect(!!(need != 0 && size > ((18446744073709551615UL
) / need)),0));
57}
58
59_malloc___attribute__ ((malloc)) _alloc_(1, 2) static inline void *malloc_multiply(size_t size, size_t need) {
60 if (size_multiply_overflow(size, need))
7
←
Taking false branch
→
61 return NULL((void*)0);
62
63 return malloc(size * need);
8
←
Memory is allocated
→
64}
65
66#if !HAVE_REALLOCARRAY1
67_alloc_(2, 3) static inline void *reallocarray(void *p, size_t need, size_t size) {
68 if (size_multiply_overflow(size, need))
69 return NULL((void*)0);
70
71 return realloc(p, size * need);
72}
73#endif
74
75_alloc_(2, 3) static inline void *memdup_multiply(const void *p, size_t size, size_t need) {
76 if (size_multiply_overflow(size, need))
77 return NULL((void*)0);
78
79 return memdup(p, size * need);
80}
81
82_alloc_(2, 3) static inline void *memdup_suffix0_multiply(const void *p, size_t size, size_t need) {
83 if (size_multiply_overflow(size, need))
84 return NULL((void*)0);
85
86 return memdup_suffix0(p, size * need);
87}
88
89void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size);
90void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size);
91
92#define GREEDY_REALLOC(array, allocated, need)greedy_realloc((void**) &(array), &(allocated), (need
), sizeof((array)[0])) \
93 greedy_realloc((void**) &(array), &(allocated), (need), sizeof((array)[0]))
94
95#define GREEDY_REALLOC0(array, allocated, need)greedy_realloc0((void**) &(array), &(allocated), (need
), sizeof((array)[0])) \
96 greedy_realloc0((void**) &(array), &(allocated), (need), sizeof((array)[0]))
97
98#define alloca0(n)({ char *_new_; size_t _len_ = n; _new_ = __builtin_alloca (_len_
); (void *) memset(_new_, 0, _len_); }) \
99 ({ \
100 char *_new_; \
101 size_t _len_ = n; \
102 _new_ = alloca(_len_)__builtin_alloca (_len_); \
103 (void *) memset(_new_, 0, _len_); \
104 })
105
106/* It's not clear what alignment glibc/gcc alloca() guarantee, hence provide a guaranteed safe version */
107#define alloca_align(size, align)({ void *_ptr_; size_t _mask_ = (align) - 1; _ptr_ = __builtin_alloca
((size) + _mask_); (void*)(((uintptr_t)_ptr_ + _mask_) &
~_mask_); }) \
108 ({ \
109 void *_ptr_; \
110 size_t _mask_ = (align) - 1; \
111 _ptr_ = alloca((size) + _mask_)__builtin_alloca ((size) + _mask_); \
112 (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_); \
113 })
114
115#define alloca0_align(size, align)({ void *_new_; size_t _size_ = (size); _new_ = ({ void *_ptr_
; size_t _mask_ = ((align)) - 1; _ptr_ = __builtin_alloca ((_size_
) + _mask_); (void*)(((uintptr_t)_ptr_ + _mask_) & ~_mask_
); }); (void*)memset(_new_, 0, _size_); }) \
116 ({ \
117 void *_new_; \
118 size_t _size_ = (size); \
119 _new_ = alloca_align(_size_, (align))({ void *_ptr_; size_t _mask_ = ((align)) - 1; _ptr_ = __builtin_alloca
((_size_) + _mask_); (void*)(((uintptr_t)_ptr_ + _mask_) &
~_mask_); }); \
120 (void*)memset(_new_, 0, _size_); \
121 })
122
123/* Takes inspiration from Rusts's Option::take() method: reads and returns a pointer, but at the same time resets it to
124 * NULL. See: https://doc.rust-lang.org/std/option/enum.Option.html#method.take */
125#define TAKE_PTR(ptr)({ typeof(ptr) _ptr_ = (ptr); (ptr) = ((void*)0); _ptr_; }) \
126 ({ \
127 typeof(ptr) _ptr_ = (ptr); \
128 (ptr) = NULL((void*)0); \
129 _ptr_; \
130 })