build: Fix musl warnings

[reinerh]

Fixes two warnings when building firejail with musl libc.

Should fix #5421.

[glitsj16]

Code looks okay. Alas I've got no way to test this properly.

[rusty-snake]

The LINE_MAX warning/error is gone. However I still get the libtrace(log) redefinition of '...' warnings/errors.

For testing I just use an podman container.

$ podman run --rm -it alpine:latest
# apk update
# apk add git build-base gawk linux-headers
# git clone --depth=1 https://github.com/netblue30/firejail.git
# cd firejail
# git fetch origin pull/5431/head:pr-5431
# git switch pr-5431
# ./configure --enable-fatal-warnings [--enable-analyzer]
# make -j4

# gcc --version
gcc (Alpine 11.2.1_git20220219) 11.2.1 20220219

libtrace(log) redefinition of '...'

In file included from /usr/include/fortify/stdio.h:22,
                 from libtrace.c:22:
libtrace.c:344:7: error: redefinition of 'fopen'
  344 | FILE *fopen64(const char *pathname, const char *mode) {
      |       ^~~~~~~
/usr/include/stdio.h:70:7: note: previous definition of 'fopen' with type 'FILE *(const char * restrict,  const char * restrict)'
   70 | FILE *fopen(const char *__restrict, const char *__restrict);
      |       ^~~~~
libtrace.c:368:7: error: redefinition of 'freopen'
  368 | FILE *freopen64(const char *pathname, const char *mode, FILE *stream) {
      |       ^~~~~~~~~
/usr/include/stdio.h:71:7: note: previous definition of 'freopen' with type 'FILE *(const char * restrict,  const char * restrict,  FILE * restrict)'
   71 | FILE *freopen(const char *__restrict, const char *__restrict, FILE *__restrict);
      |       ^~~~~~~
In file included from libtrace.c:32:
libtrace.c:448:5: error: redefinition of 'stat'
  448 | int stat64(const char *pathname, struct stat64 *statbuf) {
      |     ^~~~~~
/usr/include/sys/stat.h:73:5: note: previous definition of 'stat' with type 'int(const char * restrict,  struct stat * restrict)'
   73 | int stat(const char *__restrict, struct stat *__restrict);
      |     ^~~~
libtrace.c:471:5: error: redefinition of 'lstat'
  471 | int lstat64(const char *pathname, struct stat64 *statbuf) {
      |     ^~~~~~~
/usr/include/sys/stat.h:75:5: note: previous definition of 'lstat' with type 'int(const char * restrict,  struct stat * restrict)'
   75 | int lstat(const char *__restrict, struct stat *__restrict);
      |     ^~~~~

In file included from /usr/include/fortify/stdio.h:22,
                 from libtracelog.c:21:
libtracelog.c:408:7: error: redefinition of 'fopen'
  408 | FILE *fopen64(const char *pathname, const char *mode) {
      |       ^~~~~~~
/usr/include/stdio.h:70:7: note: previous definition of 'fopen' with type 'FILE *(const char * restrict,  const char * restrict)'
   70 | FILE *fopen(const char *__restrict, const char *__restrict);
      |       ^~~~~
libtracelog.c:444:7: error: redefinition of 'freopen'
  444 | FILE *freopen64(const char *pathname, const char *mode, FILE *stream) {
      |       ^~~~~~~~~
/usr/include/stdio.h:71:7: note: previous definition of 'freopen' with type 'FILE *(const char * restrict,  const char * restrict,  FILE * restrict)'
   71 | FILE *freopen(const char *__restrict, const char *__restrict, FILE *__restrict);
      |       ^~~~~~~
In file included from libtracelog.c:31:
libtracelog.c:566:5: error: redefinition of 'stat'
  566 | int stat64(const char *pathname, struct stat64 *buf) {
      |     ^~~~~~
/usr/include/sys/stat.h:73:5: note: previous definition of 'stat' with type 'int(const char * restrict,  struct stat * restrict)'
   73 | int stat(const char *__restrict, struct stat *__restrict);
      |     ^~~~
libtracelog.c:600:5: error: redefinition of 'lstat'
  600 | int lstat64(const char *pathname, struct stat64 *buf) {
      |     ^~~~~~~
/usr/include/sys/stat.h:75:5: note: previous definition of 'lstat' with type 'int(const char * restrict,  struct stat * restrict)'
   75 | int lstat(const char *__restrict, struct stat *__restrict);
      |     ^~~~~

Running with --enable-analyzer gives me also this list. IDK if they are false-positive.

double-'free' of 'rdest' [CWE-415] [-Werror=analyzer-double-free]

main.c: In function 'duplicate_dir':
main.c:369:9: error: double-'free' of 'rdest' [CWE-415] [-Werror=analyzer-double-free]
  369 |         free(rdest);
      |         ^~~~~~~~~~~
  'duplicate_dir': events 1-2
    |
    |  355 | static void duplicate_dir(const char *src, const char *dest, struct stat *s) {
    |      |             ^~~~~~~~~~~~~
    |      |             |
    |      |             (1) entry to 'duplicate_dir'
    |  356 |         (void) s;
    |  357 |         char *rsrc = check(src);
    |      |                      ~~~~~~~~~~
    |      |                      |
    |      |                      (2) calling 'check' from 'duplicate_dir'
    |
    +--> 'check': events 3-7
           |
           |  321 | static char *check(const char *src) {
           |      |              ^~~~~
           |      |              |
           |      |              (3) entry to 'check'
           |......
           |  324 |         if (!rsrc || stat(rsrc, &s) == -1)
           |      |            ~  
           |      |            |
           |      |            (4) following 'false' branch...
           |......
           |  330 |         uid_t user = getuid();
           |      |         ~~~~~ 
           |      |         |
           |      |         (5) ...to here
           |......
           |  340 |                 if (s.st_uid != user)
           |      |                    ~
           |      |                    |
           |      |                    (6) following 'false' branch...
           |......
           |  345 |         if (S_ISDIR(s.st_mode) || S_ISREG(s.st_mode) || S_ISLNK(s.st_mode))
           |      |         ~~    
           |      |         |
           |      |         (7) ...to here
           |
    <------+
    |
  'duplicate_dir': events 8-9
    |
    |  357 |         char *rsrc = check(src);
    |      |                      ^~~~~~~~~~
    |      |                      |
    |      |                      (8) returning to 'duplicate_dir' from 'check'
    |  358 |         char *rdest = check(dest);
    |      |                       ~~~~~~~~~~~
    |      |                       |
    |      |                       (9) calling 'check' from 'duplicate_dir'
    |
    +--> 'check': events 10-14
           |
           |  321 | static char *check(const char *src) {
           |      |              ^~~~~
           |      |              |
           |      |              (10) entry to 'check'
           |......
           |  324 |         if (!rsrc || stat(rsrc, &s) == -1)
           |      |            ~  
           |      |            |
           |      |            (11) following 'false' branch...
           |......
           |  330 |         uid_t user = getuid();
           |      |         ~~~~~ 
           |      |         |
           |      |         (12) ...to here
           |......
           |  340 |                 if (s.st_uid != user)
           |      |                    ~
           |      |                    |
           |      |                    (13) following 'false' branch...
           |......
           |  345 |         if (S_ISDIR(s.st_mode) || S_ISREG(s.st_mode) || S_ISLNK(s.st_mode))
           |      |         ~~    
           |      |         |
           |      |         (14) ...to here
           |
    <------+
    |
  'duplicate_dir': events 15-19
    |
    |  358 |         char *rdest = check(dest);
    |      |                       ^~~~~~~~~~~
    |      |                       |
    |      |                       (15) returning to 'duplicate_dir' from 'check'
    |......
    |  363 |         if(nftw(rsrc, fs_copydir, 1, FTW_PHYS) != 0) {
    |      |           ~            
    |      |           |
    |      |           (16) following 'false' branch...
    |......
    |  368 |         free(rsrc);
    |      |         ~~~~~~~~~~     
    |      |         |
    |      |         (17) ...to here
    |      |         (18) first 'free' here
    |  369 |         free(rdest);
    |      |         ~~~~~~~~~~~    
    |      |         |
    |      |         (19) second 'free' here; first 'free' was at (18)
    |

double-'free' of 'rdest' [CWE-415] [-Werror=analyzer-double-free]

main.c: In function 'duplicate_file':
main.c:392:9: error: double-'free' of 'rdest' [CWE-415] [-Werror=analyzer-double-free]
  392 |         free(rdest);
      |         ^~~~~~~~~~~
  'duplicate_file': events 1-2
    |
    |  373 | static void duplicate_file(const char *src, const char *dest, struct stat *s) {
    |      |             ^~~~~~~~~~~~~~
    |      |             |
    |      |             (1) entry to 'duplicate_file'
    |  374 |         char *rsrc = check(src);
    |      |                      ~~~~~~~~~~
    |      |                      |
    |      |                      (2) calling 'check' from 'duplicate_file'
    |
    +--> 'check': events 3-7
           |
           |  321 | static char *check(const char *src) {
           |      |              ^~~~~
           |      |              |
           |      |              (3) entry to 'check'
           |......
           |  324 |         if (!rsrc || stat(rsrc, &s) == -1)
           |      |            ~  
           |      |            |
           |      |            (4) following 'false' branch...
           |......
           |  330 |         uid_t user = getuid();
           |      |         ~~~~~ 
           |      |         |
           |      |         (5) ...to here
           |......
           |  340 |                 if (s.st_uid != user)
           |      |                    ~
           |      |                    |
           |      |                    (6) following 'false' branch...
           |......
           |  345 |         if (S_ISDIR(s.st_mode) || S_ISREG(s.st_mode) || S_ISLNK(s.st_mode))
           |      |         ~~    
           |      |         |
           |      |         (7) ...to here
           |
    <------+
    |
  'duplicate_file': events 8-9
    |
    |  374 |         char *rsrc = check(src);
    |      |                      ^~~~~~~~~~
    |      |                      |
    |      |                      (8) returning to 'duplicate_file' from 'check'
    |  375 |         char *rdest = check(dest);
    |      |                       ~~~~~~~~~~~
    |      |                       |
    |      |                       (9) calling 'check' from 'duplicate_file'
    |
    +--> 'check': events 10-14
           |
           |  321 | static char *check(const char *src) {
           |      |              ^~~~~
           |      |              |
           |      |              (10) entry to 'check'
           |......
           |  324 |         if (!rsrc || stat(rsrc, &s) == -1)
           |      |            ~  
           |      |            |
           |      |            (11) following 'false' branch...
           |......
           |  330 |         uid_t user = getuid();
           |      |         ~~~~~ 
           |      |         |
           |      |         (12) ...to here
           |......
           |  340 |                 if (s.st_uid != user)
           |      |                    ~
           |      |                    |
           |      |                    (13) following 'false' branch...
           |......
           |  345 |         if (S_ISDIR(s.st_mode) || S_ISREG(s.st_mode) || S_ISLNK(s.st_mode))
           |      |         ~~    
           |      |         |
           |      |         (14) ...to here
           |
    <------+
    |
  'duplicate_file': events 15-16
    |
    |  375 |         char *rdest = check(dest);
    |      |                       ^~~~~~~~~~~
    |      |                       |
    |      |                       (15) returning to 'duplicate_file' from 'check'
    |......
    |  384 |         if (asprintf(&name, "%s/%s", rdest, ptr) == -1)
    |      |            ~           
    |      |            |
    |      |            (16) following 'false' branch...
    |
  'duplicate_file': event 17
    |
    |../include/common.h:39:28:
    |   39 | #define errExit(msg)    do { char msgout[500]; snprintf(msgout, 500, "Error %s: %s:%d %s", msg, __FILE__, __LINE__, __FUNCTION__); perror(msgout); exit(1);} while (0)
    |      |                            ^
    |      |                            |
    |      |                            (17) ...to here
main.c:385:17: note: in expansion of macro 'errExit'
    |  385 |                 errExit("asprintf");
    |      |                 ^~~~~~~
    |
  'duplicate_file': event 18
    |
    |  388 |         copy_file(rsrc, name, mode, uid, gid);
    |      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    |      |         |
    |      |         (18) calling 'copy_file' from 'duplicate_file'
    |
    +--> 'copy_file': event 19
           |
           |  104 | static void copy_file(const char *srcname, const char *destname, mode_t mode, uid_t uid, gid_t gid) {
           |      |             ^~~~~~~~~
           |      |             |
           |      |             (19) entry to 'copy_file'
           |
         'copy_file': event 20
           |
           |  105 |         assert(srcname);
           |      |         ^~~~~~
           |      |         |
           |      |         (20) following 'true' branch (when 'srcname' is non-NULL)...
           |
         'copy_file': event 21
           |
           |  106 |         assert(destname);
           |      |         ^~~~~~
           |      |         |
           |      |         (21) ...to here
           |
         'copy_file': event 22
           |
           |  106 |         assert(destname);
           |      |         ^~~~~~
           |      |         |
           |      |         (22) following 'true' branch (when 'destname' is non-NULL)...
           |
         'copy_file': event 23
           |
           |  107 |         mode &= 07777;
           |      |         ^~~~
           |      |         |
           |      |         (23) ...to here
           |
    <------+
    |
  'duplicate_file': events 24-26
    |
    |  388 |         copy_file(rsrc, name, mode, uid, gid);
    |      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    |      |         |
    |      |         (24) returning to 'duplicate_file' from 'copy_file'
    |......
    |  391 |         free(rsrc);
    |      |         ~~~~~~~~~~
    |      |         |
    |      |         (25) first 'free' here
    |  392 |         free(rdest);
    |      |         ~~~~~~~~~~~
    |      |         |
    |      |         (26) second 'free' here; first 'free' was at (25)
    |

double-'free' of 'rdest' [CWE-415] [-Werror=analyzer-double-free]

main.c: In function 'duplicate_link':
main.c:416:9: error: double-'free' of 'rdest' [CWE-415] [-Werror=analyzer-double-free]
  416 |         free(rdest);
      |         ^~~~~~~~~~~
  'duplicate_link': events 1-2
    |
    |  396 | static void duplicate_link(const char *src, const char *dest, struct stat *s) {
    |      |             ^~~~~~~~~~~~~~
    |      |             |
    |      |             (1) entry to 'duplicate_link'
    |  397 |         char *rsrc = check(src);                  // we drop the result and use the original name
    |      |                      ~~~~~~~~~~
    |      |                      |
    |      |                      (2) calling 'check' from 'duplicate_link'
    |
    +--> 'check': events 3-7
           |
           |  321 | static char *check(const char *src) {
           |      |              ^~~~~
           |      |              |
           |      |              (3) entry to 'check'
           |......
           |  324 |         if (!rsrc || stat(rsrc, &s) == -1)
           |      |            ~  
           |      |            |
           |      |            (4) following 'false' branch...
           |......
           |  330 |         uid_t user = getuid();
           |      |         ~~~~~ 
           |      |         |
           |      |         (5) ...to here
           |......
           |  340 |                 if (s.st_uid != user)
           |      |                    ~
           |      |                    |
           |      |                    (6) following 'false' branch...
           |......
           |  345 |         if (S_ISDIR(s.st_mode) || S_ISREG(s.st_mode) || S_ISLNK(s.st_mode))
           |      |         ~~    
           |      |         |
           |      |         (7) ...to here
           |
    <------+
    |
  'duplicate_link': events 8-9
    |
    |  397 |         char *rsrc = check(src);                  // we drop the result and use the original name
    |      |                      ^~~~~~~~~~
    |      |                      |
    |      |                      (8) returning to 'duplicate_link' from 'check'
    |  398 |         char *rdest = check(dest);
    |      |                       ~~~~~~~~~~~
    |      |                       |
    |      |                       (9) calling 'check' from 'duplicate_link'
    |
    +--> 'check': events 10-14
           |
           |  321 | static char *check(const char *src) {
           |      |              ^~~~~
           |      |              |
           |      |              (10) entry to 'check'
           |......
           |  324 |         if (!rsrc || stat(rsrc, &s) == -1)
           |      |            ~  
           |      |            |
           |      |            (11) following 'false' branch...
           |......
           |  330 |         uid_t user = getuid();
           |      |         ~~~~~ 
           |      |         |
           |      |         (12) ...to here
           |......
           |  340 |                 if (s.st_uid != user)
           |      |                    ~
           |      |                    |
           |      |                    (13) following 'false' branch...
           |......
           |  345 |         if (S_ISDIR(s.st_mode) || S_ISREG(s.st_mode) || S_ISLNK(s.st_mode))
           |      |         ~~    
           |      |         |
           |      |         (14) ...to here
           |
    <------+
    |
  'duplicate_link': events 15-16
    |
    |  398 |         char *rdest = check(dest);
    |      |                       ^~~~~~~~~~~
    |      |                       |
    |      |                       (15) returning to 'duplicate_link' from 'check'
    |......
    |  408 |         if (asprintf(&name, "%s/%s", rdest, ptr) == -1)
    |      |            ~           
    |      |            |
    |      |            (16) following 'false' branch...
    |
  'duplicate_link': event 17
    |
    |../include/common.h:39:28:
    |   39 | #define errExit(msg)    do { char msgout[500]; snprintf(msgout, 500, "Error %s: %s:%d %s", msg, __FILE__, __LINE__, __FUNCTION__); perror(msgout); exit(1);} while (0)
    |      |                            ^
    |      |                            |
    |      |                            (17) ...to here
main.c:409:17: note: in expansion of macro 'errExit'
    |  409 |                 errExit("asprintf");
    |      |                 ^~~~~~~
    |
  'duplicate_link': events 18-19
    |
    |  415 |         free(rsrc);
    |      |         ^~~~~~~~~~
    |      |         |
    |      |         (18) first 'free' here
    |  416 |         free(rdest);
    |      |         ~~~~~~~~~~~
    |      |         |
    |      |         (19) second 'free' here; first 'free' was at (18)
    |

use of possibly-NULL 'strdup(fname)' where non-null expected [CWE-690] [-Werror=analyzer-possible-null-argument]

filedb.c: In function 'filedb_add.part.0':
filedb.c:69:22: error: use of possibly-NULL 'strdup(fname)' where non-null expected [CWE-690] [-Werror=analyzer-possible-null-argument]
   69 |         entry->len = strlen(entry->fname);
      |                      ^~~~~~~~~~~~~~~~~~~~
  'filedb_load_whitelist': event 1
    |
    |   88 | FileDB *filedb_load_whitelist(FileDB *head, const char *fname, const char *prefix) {
    |      |         ^~~~~~~~~~~~~~~~~~~~~
    |      |         |
    |      |         (1) entry to 'filedb_load_whitelist'
    |
  'filedb_load_whitelist': event 2
    |
    |   89 |         assert(fname);
    |      |         ^~~~~~
    |      |         |
    |      |         (2) following 'true' branch (when 'fname' is non-NULL)...
    |
  'filedb_load_whitelist': event 3
    |
    |   90 |         assert(prefix);
    |      |         ^~~~~~
    |      |         |
    |      |         (3) ...to here
    |
  'filedb_load_whitelist': event 4
    |
    |   90 |         assert(prefix);
    |      |         ^~~~~~
    |      |         |
    |      |         (4) following 'true' branch (when 'prefix' is non-NULL)...
    |
  'filedb_load_whitelist': events 5-6
    |
    |   91 |         int len = strlen(prefix);
    |      |         ^~~
    |      |         |
    |      |         (5) ...to here
    |   92 |         char *f;
    |   93 |         if (asprintf(&f, "%s/%s", SYSCONFDIR, fname) == -1)
    |      |            ~
    |      |            |
    |      |            (6) following 'false' branch...
    |
  'filedb_load_whitelist': event 7
    |
    |../include/common.h:39:28:
    |   39 | #define errExit(msg)    do { char msgout[500]; snprintf(msgout, 500, "Error %s: %s:%d %s", msg, __FILE__, __LINE__, __FUNCTION__); perror(msgout); exit(1);} while (0)
    |      |                            ^
    |      |                            |
    |      |                            (7) ...to here
filedb.c:94:17: note: in expansion of macro 'errExit'
    |   94 |                 errExit("asprintf");
    |      |                 ^~~~~~~
    |
  'filedb_load_whitelist': event 8
    |
    |   96 |         if (!fp) {
    |      |            ^
    |      |            |
    |      |            (8) following 'false' branch (when 'fp' is non-NULL)...
    |
  'filedb_load_whitelist': event 9
    |
    |cc1:
    | (9): ...to here
    |
  'filedb_load_whitelist': events 10-12
    |
    |  103 |         while (fgets(buf, MAX_BUF, fp)) {
    |      |                ^~~~~
    |      |                |
    |      |                (10) following 'true' branch...
    |  104 |                 if (strncmp(buf, prefix, len) != 0)
    |      |                 ~~
    |      |                 |
    |      |                 (11) ...to here
    |......
    |  114 |                 head = filedb_add(head, fn);
    |      |                        ~~~~~~~~~~~~~~~~~~~~
    |      |                        |
    |      |                        (12) calling 'filedb_add' from 'filedb_load_whitelist'
    |
    +--> 'filedb_add': event 13
           |
           |   54 | FileDB *filedb_add(FileDB *head, const char *fname) {
           |      |         ^~~~~~~~~~
           |      |         |
           |      |         (13) entry to 'filedb_add'
           |
         'filedb_add': event 14
           |
           |   55 |         assert(fname);
           |      |         ^~~~~~
           |      |         |
           |      |         (14) following 'true' branch (when 'fname' is non-NULL)...
           |
         'filedb_add': events 15-16
           |
           |   58 |         if (filedb_find(head, fname))
           |      |         ^~  ~~~~~~~~~~~~~~~~~~~~~~~~
           |      |         |   |
           |      |         |   (16) calling 'filedb_find' from 'filedb_add'
           |      |         (15) ...to here
           |
           +--> 'filedb_find': event 17
                  |
                  |   24 | FileDB *filedb_find(FileDB *head, const char *fname) {
                  |      |         ^~~~~~~~~~~
                  |      |         |
                  |      |         (17) entry to 'filedb_find'
                  |
                'filedb_find': event 18
                  |
                  |   25 |         assert(fname);
                  |      |         ^~~~~~
                  |      |         |
                  |      |         (18) following 'true' branch (when 'fname' is non-NULL)...
                  |
                'filedb_find': event 19
                  |
                  |cc1:
                  | (19): ...to here
                  |
                'filedb_find': event 20
                  |
                  |cc1:
                  | (20): calling 'filedb_find.part.0' from 'filedb_find'
                  |
                  +--> 'filedb_find.part.0': events 21-27
                         |
                         |   24 | FileDB *filedb_find(FileDB *head, const char *fname) {
                         |      |         ^~~~~~~~~~~
                         |      |         |
                         |      |         (21) entry to 'filedb_find.part.0'
                         |......
                         |   29 |         while (ptr) {
                         |      |                ~~~
                         |      |                |
                         |      |                (22) following 'true' branch (when 'ptr' is non-NULL)...
                         |      |                (24) following 'true' branch (when 'ptr' is non-NULL)...
                         |......
                         |   32 |                 if (fnmatch(ptr->fname, fname, FNM_PATHNAME) == 0) {
                         |      |                 ~~
                         |      |                 |
                         |      |                 (23) ...to here
                         |      |                 (25) ...to here
                         |......
                         |   48 |         if (found)
                         |      |            ~
                         |      |            |
                         |      |            (26) following 'true' branch (when 'found != 0')...
                         |   49 |                 return ptr;
                         |      |                 ~~~~~~
                         |      |                 |
                         |      |                 (27) ...to here
                         |
                  <------+
                  |
                'filedb_find': event 28
                  |
                  |cc1:
                  | (28): returning to 'filedb_find' from 'filedb_find.part.0'
                  |
           <------+
           |
         'filedb_add': event 29
           |
           |   58 |         if (filedb_find(head, fname))
           |      |             ^~~~~~~~~~~~~~~~~~~~~~~~
           |      |             |
           |      |             (29) returning to 'filedb_add' from 'filedb_find'
           |
         'filedb_add': event 30
           |
           |cc1:
           | (30): calling 'filedb_add.part.0' from 'filedb_add'
           |
           +--> 'filedb_add.part.0': events 31-32
                  |
                  |   54 | FileDB *filedb_add(FileDB *head, const char *fname) {
                  |      |         ^~~~~~~~~~
                  |      |         |
                  |      |         (31) entry to 'filedb_add.part.0'
                  |......
                  |   63 |         if (!entry)
                  |      |            ~
                  |      |            |
                  |      |            (32) following 'false' branch (when 'entry' is non-NULL)...
                  |
                'filedb_add.part.0': event 33
                  |
                  |../include/common.h:39:28:
                  |   39 | #define errExit(msg)    do { char msgout[500]; snprintf(msgout, 500, "Error %s: %s:%d %s", msg, __FILE__, __LINE__, __FUNCTION__); perror(msgout); exit(1);} while (0)
                  |      |                            ^
                  |      |                            |
                  |      |                            (33) ...to here
filedb.c:64:17: note: in expansion of macro 'errExit'
                  |   64 |                 errExit("malloc");
                  |      |                 ^~~~~~~
                  |
                'filedb_add.part.0': events 34-35
                  |
                  |/usr/include/fortify/string.h:70:12:
                  |   70 |         if (__n > __b)
                  |      |            ^
                  |      |            |
                  |      |            (34) following 'false' branch (when '__b > 23')...
                  |   71 |                 __builtin_trap();
                  |   72 |         return __builtin_memset(__d, __c, __n);
                  |      |         ~~~~~~
                  |      |         |
                  |      |         (35) ...to here
                  |
                'filedb_add.part.0': events 36-38
                  |
                  |filedb.c:66:24:
                  |   66 |         entry->fname = strdup(fname);
                  |      |                        ^~~~~~~~~~~~~
                  |      |                        |
                  |      |                        (36) this call could return NULL
                  |   67 |         if (!entry->fname)
                  |      |            ~            
                  |      |            |
                  |      |            (37) assuming 'strdup(fname)' is non-NULL
                  |      |            (38) following 'false' branch...
                  |
                'filedb_add.part.0': event 39
                  |
                  |../include/common.h:39:28:
                  |   39 | #define errExit(msg)    do { char msgout[500]; snprintf(msgout, 500, "Error %s: %s:%d %s", msg, __FILE__, __LINE__, __FUNCTION__); perror(msgout); exit(1);} while (0)
                  |      |                            ^
                  |      |                            |
                  |      |                            (39) ...to here
filedb.c:68:17: note: in expansion of macro 'errExit'
                  |   68 |                 errExit("strdup");
                  |      |                 ^~~~~~~
                  |
           <------+
           |
         'filedb_add': event 40
           |
           |cc1:
           | (40): returning to 'filedb_add' from 'filedb_add.part.0'
           |
    <------+
    |
  'filedb_load_whitelist': events 41-48
    |
    |  103 |         while (fgets(buf, MAX_BUF, fp)) {
    |      |                ~~~~~    
    |      |                |
    |      |                (42) following 'true' branch...
    |  104 |                 if (strncmp(buf, prefix, len) != 0)
    |      |                 ~~ ~    
    |      |                 |  |
    |      |                 |  (44) following 'false' branch...
    |      |                 (43) ...to here
    |......
    |  107 |                 char *fn = buf + len;
    |      |                 ~~~~    
    |      |                 |
    |      |                 (45) ...to here
    |  108 |                 char *ptr = strchr(buf, '\n');
    |  109 |                 if (!ptr)
    |      |                    ~    
    |      |                    |
    |      |                    (46) following 'false' branch (when 'ptr' is non-NULL)...
    |  110 |                         continue;
    |  111 |                 *ptr = '\0';
    |      |                 ~       
    |      |                 |
    |      |                 (47) ...to here
    |......
    |  114 |                 head = filedb_add(head, fn);
    |      |                        ^~~~~~~~~~~~~~~~~~~~
    |      |                        |
    |      |                        (41) returning to 'filedb_load_whitelist' from 'filedb_add'
    |      |                        (48) calling 'filedb_add' from 'filedb_load_whitelist'
    |
    +--> 'filedb_add': event 49
           |
           |   54 | FileDB *filedb_add(FileDB *head, const char *fname) {
           |      |         ^~~~~~~~~~
           |      |         |
           |      |         (49) entry to 'filedb_add'
           |
         'filedb_add': event 50
           |
           |   55 |         assert(fname);
           |      |         ^~~~~~
           |      |         |
           |      |         (50) following 'true' branch (when 'fname' is non-NULL)...
           |
         'filedb_add': events 51-52
           |
           |   58 |         if (filedb_find(head, fname))
           |      |         ^~  ~~~~~~~~~~~~~~~~~~~~~~~~
           |      |         |   |
           |      |         |   (52) calling 'filedb_find' from 'filedb_add'
           |      |         (51) ...to here
           |
           +--> 'filedb_find': event 53
                  |
                  |   24 | FileDB *filedb_find(FileDB *head, const char *fname) {
                  |      |         ^~~~~~~~~~~
                  |      |         |
                  |      |         (53) entry to 'filedb_find'
                  |
                'filedb_find': event 54
                  |
                  |   25 |         assert(fname);
                  |      |         ^~~~~~
                  |      |         |
                  |      |         (54) following 'true' branch (when 'fname' is non-NULL)...
                  |
                'filedb_find': event 55
                  |
                  |cc1:
                  | (55): ...to here
                  |
                'filedb_find': event 56
                  |
                  |cc1:
                  | (56): calling 'filedb_find.part.0' from 'filedb_find'
                  |
                  +--> 'filedb_find.part.0': events 57-62
                         |
                         |   24 | FileDB *filedb_find(FileDB *head, const char *fname) {
                         |      |         ^~~~~~~~~~~
                         |      |         |
                         |      |         (57) entry to 'filedb_find.part.0'
                         |......
                         |   29 |         while (ptr) {
                         |      |                ~~~
                         |      |                |
                         |      |                (58) following 'true' branch (when 'ptr' is non-NULL)...
                         |......
                         |   32 |                 if (fnmatch(ptr->fname, fname, FNM_PATHNAME) == 0) {
                         |      |                 ~~ ~
                         |      |                 |  |
                         |      |                 |  (60) following 'false' branch...
                         |      |                 (59) ...to here
                         |......
                         |   38 |                 if (strlen(fname) > ptr->len &&
                         |      |                 ~~
                         |      |                 |
                         |      |                 (61) ...to here
                         |......
                         |   48 |         if (found)
                         |      |            ~
                         |      |            |
                         |      |            (62) following 'false' branch (when 'found == 0')...
                         |
                       'filedb_find.part.0': event 63
                         |
                         |cc1:
                         | (63): ...to here
                         |
                  <------+
                  |
                'filedb_find': event 64
                  |
                  |cc1:
                  | (64): returning to 'filedb_find' from 'filedb_find.part.0'
                  |
           <------+
           |
         'filedb_add': events 65-66
           |
           |   58 |         if (filedb_find(head, fname))
           |      |            ~^~~~~~~~~~~~~~~~~~~~~~~~
           |      |            ||
           |      |            |(65) returning to 'filedb_add' from 'filedb_find'
           |      |            (66) following 'false' branch...
           |
         'filedb_add': event 67
           |
           |cc1:
           | (67): ...to here
           |
         'filedb_add': event 68
           |
           |cc1:
           | (68): calling 'filedb_add.part.0' from 'filedb_add'
           |
           +--> 'filedb_add.part.0': events 69-70
                  |
                  |   54 | FileDB *filedb_add(FileDB *head, const char *fname) {
                  |      |         ^~~~~~~~~~
                  |      |         |
                  |      |         (69) entry to 'filedb_add.part.0'
                  |......
                  |   63 |         if (!entry)
                  |      |            ~
                  |      |            |
                  |      |            (70) following 'false' branch (when 'entry' is non-NULL)...
                  |
                'filedb_add.part.0': event 71
                  |
                  |../include/common.h:39:28:
                  |   39 | #define errExit(msg)    do { char msgout[500]; snprintf(msgout, 500, "Error %s: %s:%d %s", msg, __FILE__, __LINE__, __FUNCTION__); perror(msgout); exit(1);} while (0)
                  |      |                            ^
                  |      |                            |
                  |      |                            (71) ...to here
filedb.c:64:17: note: in expansion of macro 'errExit'
                  |   64 |                 errExit("malloc");
                  |      |                 ^~~~~~~
                  |
                'filedb_add.part.0': events 72-73
                  |
                  |/usr/include/fortify/string.h:70:12:
                  |   70 |         if (__n > __b)
                  |      |            ^
                  |      |            |
                  |      |            (72) following 'false' branch (when '__b > 23')...
                  |   71 |                 __builtin_trap();
                  |   72 |         return __builtin_memset(__d, __c, __n);
                  |      |         ~~~~~~
                  |      |         |
                  |      |         (73) ...to here
                  |
                'filedb_add.part.0': events 74-75
                  |
                  |filedb.c:66:24:
                  |   66 |         entry->fname = strdup(fname);
                  |      |                        ^~~~~~~~~~~~~
                  |      |                        |
                  |      |                        (74) this call could return NULL
                  |   67 |         if (!entry->fname)
                  |      |            ~            
                  |      |            |
                  |      |            (75) following 'false' branch...
                  |
                'filedb_add.part.0': event 76
                  |
                  |../include/common.h:39:28:
                  |   39 | #define errExit(msg)    do { char msgout[500]; snprintf(msgout, 500, "Error %s: %s:%d %s", msg, __FILE__, __LINE__, __FUNCTION__); perror(msgout); exit(1);} while (0)
                  |      |                            ^
                  |      |                            |
                  |      |                            (76) ...to here
filedb.c:68:17: note: in expansion of macro 'errExit'
                  |   68 |                 errExit("strdup");
                  |      |                 ^~~~~~~
                  |
                'filedb_add.part.0': event 77
                  |
                  |   69 |         entry->len = strlen(entry->fname);
                  |      |                      ^~~~~~~~~~~~~~~~~~~~
                  |      |                      |
                  |      |                      (77) argument 1 ('strdup(fname)') from (74) could be NULL where non-null expected
                  |

note: argument 1 of 'strlen' must be non-null

In file included from /usr/include/fortify/string.h:22,
                 from ../include/common.h:31,
                 from fbuilder.h:23,
                 from filedb.c:21:
/usr/include/string.h:54:8: note: argument 1 of 'strlen' must be non-null
   54 | size_t strlen (const char *);
      |        ^~~~~~

[reinerh]

Thanks! I'll have a closer look at it.

[reinerh]

The non-null warning looks like a false-positive to me:

        entry->fname = strdup(fname);
        if (!entry->fname)
                errExit("strdup");
        entry->len = strlen(entry->fname);

Even if strdup returns NULL, I don't see how NULL could get passed to strlen, as it would have exited...

[reinerh]

@rusty-snake I just checked with an alpine:edge container, which has gcc-12.
There it successfully builds with enabled analyzer.