Drop alloca(3)

alloca(3) fails silently if not enough memory can be allocated on the
stack.  Use checked dynamic allocation instead.

Also drop unnecessary manual NUL assignment, ensured by snprintf(3).

Co-developed-by: Alejandro Colomar <alx@kernel.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

diff --git a/lib/alloc.h b/lib/alloc.h
index 64984f3a8a2ce2c4feacf6bb5e9ca869958c77aa..2b1599cb1e58c572ae1bc3f4470e37b0ad24cd61 100644 (file)
--- a/lib/alloc.h
+++ b/lib/alloc.h
@@ -20,13 +20,11 @@
 #include "defines.h"
 
 
-#define ALLOCARRAY(n, type)    ((type *) alloca(sizeof(type) * (n)))
 #define CALLOC(n, type)        ((type *) calloc(n, sizeof(type)))
 #define XCALLOC(n, type)       ((type *) xcalloc(n, sizeof(type)))
 #define MALLOCARRAY(n, type)   ((type *) mallocarray(n, sizeof(type)))
 #define XMALLOCARRAY(n, type)  ((type *) xmallocarray(n, sizeof(type)))
 
-#define ALLOCA(type)           ALLOCARRAY(1, type)
 #define MALLOC(type)           MALLOCARRAY(1, type)
 #define XMALLOC(type)          XMALLOCARRAY(1, type)
 #define REALLOC(ptr, type)     REALLOCARRAY(ptr, 1, type)

diff --git a/libmisc/getdate.y b/libmisc/getdate.y
index 0c07f7466a9477839e50fa76fa8482fd12ebeb38..2e13e2dc903dcb44e7237a2e17af02731e390024 100644 (file)
--- a/libmisc/getdate.y
+++ b/libmisc/getdate.y
@@ -12,9 +12,6 @@
 
 #ifdef HAVE_CONFIG_H
 # include <config.h>
-# ifdef FORCE_ALLOCA_H
-#  include <alloca.h>
-# endif
 #endif
 
 /* Since the code of getdate.y is not included in the Emacs executable

diff --git a/src/useradd.c b/src/useradd.c
index e3123615547f51c6fcb6c1048a4cadaeea4770e7..bb5f4bc81d671b4692365a287934d991e47b0934 100644 (file)
--- a/src/useradd.c
+++ b/src/useradd.c
@@ -2435,6 +2435,7 @@ static void create_mail (void)
        if (strcasecmp (create_mail_spool, "yes") == 0) {
                const char *spool;
                char *file;
+               size_t size;
                int fd;
                struct group *gr;
                gid_t gid;
@@ -2449,7 +2450,8 @@ static void create_mail (void)
                if (NULL == spool) {
                        return;
                }
-               file = ALLOCARRAY (strlen (prefix) + strlen (spool) + strlen (user_name) + 3, char);
+               size = strlen(prefix) + strlen(spool) + strlen(user_name) + 3;
+               file = XMALLOCARRAY(size, char);
                if (prefix[0])
                        sprintf (file, "%s/%s/%s", prefix, spool, user_name);
                else
@@ -2465,6 +2467,8 @@ static void create_mail (void)
 #endif
 
                fd = open (file, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0);
+               free(file);
+
                if (fd < 0) {
                        perror (_("Creating mailbox file"));
                        return;

diff --git a/src/usermod.c b/src/usermod.c
index db5d37a4265ea8effe570fbf5f66c8424c8acff0..6a61576b0b4ce08ea340ca381521586aa82381eb 100644 (file)
--- a/src/usermod.c
+++ b/src/usermod.c
@@ -2034,10 +2034,9 @@ static void move_mailbox (void)
 {
        const char *maildir;
        char* mailfile;
-       char* newmailfile;
        int fd;
        struct stat st;
-       size_t len;
+       size_t size;
 
        maildir = getdef_str ("MAIL_DIR");
 #ifdef MAIL_SPOOL_DIR
@@ -2048,8 +2047,8 @@ static void move_mailbox (void)
        if (NULL == maildir) {
                return;
        }
-       len = strlen (prefix) + strlen (maildir) + strlen (user_name) + 3;
-       mailfile = ALLOCARRAY (len, char);
+       size = strlen(prefix) + strlen(maildir) + strlen(user_name) + 3;
+       mailfile = XMALLOCARRAY(size, char);
 
        /*
         * O_NONBLOCK is to make sure open won't hang on mandatory locks.
@@ -2058,14 +2057,13 @@ static void move_mailbox (void)
         * between stat and chown).  --marekm
         */
        if (prefix[0]) {
-               (void) snprintf (mailfile, len, "%s/%s/%s",
+               (void) snprintf (mailfile, size, "%s/%s/%s",
                             prefix, maildir, user_name);
        }
        else {
-               (void) snprintf (mailfile, len, "%s/%s",
+               (void) snprintf (mailfile, size, "%s/%s",
                             maildir, user_name);
        }
-       mailfile[len-1] = '\0';
 
        fd = open (mailfile, O_RDONLY | O_NONBLOCK, 0);
        if (fd < 0) {
@@ -2073,11 +2071,13 @@ static void move_mailbox (void)
                if (errno != ENOENT) {
                        perror (mailfile);
                }
+               free(mailfile);
                return;
        }
        if (fstat (fd, &st) < 0) {
                perror ("fstat");
                (void) close (fd);
+               free(mailfile);
                return;
        }
        if (st.st_uid != user_id) {
@@ -2085,6 +2085,7 @@ static void move_mailbox (void)
                fprintf (stderr, _("%s: warning: %s not owned by %s\n"),
                         Prog, mailfile, user_name);
                (void) close (fd);
+               free(mailfile);
                return;
        }
        if (uflg) {
@@ -2103,17 +2104,19 @@ static void move_mailbox (void)
        (void) close (fd);
 
        if (lflg) {
-               len = strlen (prefix) + strlen (maildir) + strlen (user_newname) + 3;
-               newmailfile = ALLOCARRAY(len, char);
+               char* newmailfile;
+               size_t newsize;
+
+               newsize = strlen(prefix) + strlen(maildir) + strlen(user_newname) + 3;
+               newmailfile = XMALLOCARRAY(newsize, char);
                if (prefix[0]) {
-                       (void) snprintf (newmailfile, len, "%s/%s/%s",
+                       (void) snprintf (newmailfile, newsize, "%s/%s/%s",
                                         prefix, maildir, user_newname);
                }
                else {
-                       (void) snprintf (newmailfile, len, "%s/%s",
+                       (void) snprintf (newmailfile, newsize, "%s/%s",
                                         maildir, user_newname);
                }
-               newmailfile[len - 1] = '\0';
                if (   (link (mailfile, newmailfile) != 0)
                    || (unlink (mailfile) != 0)) {
                        perror (_("failed to rename mailbox"));
@@ -2124,8 +2127,12 @@ static void move_mailbox (void)
                                      "changing mail file name",
                                      user_newname, user_newid, 1);
                }
+
+               free(newmailfile);
 #endif
        }
+
+       free(mailfile);
 }
 #endif