file: uci_file_commit: fix memory leak

Fixes following memory leak:

 26 bytes in 1 blocks are definitely lost in loss record 1 of 1
   at 0x4C2FB0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
   by 0x52DA68F: vasprintf (vasprintf.c:73)
   by 0x52B71D3: asprintf (asprintf.c:35)
   by 0x4E40F67: uci_file_commit (file.c:738)
   by 0x4E3FD94: uci_commit (libuci.c:193)
   by 0x401ED9: uci_do_import (cli.c:408)
   by 0x401ED9: uci_cmd (cli.c:685)
   by 0x4016FA: main (cli.c:776)

Signed-off-by: Petr Štetiar <ynezz@true.cz>

diff --git a/file.c b/file.c
index 23bf49a16f631070b55a0909c733a167b432dfb4..5502a4286d7f8ffec4095e64dde61a140d5051cc 100644 (file)
--- a/file.c
+++ b/file.c
@@ -33,6 +33,10 @@
 #include "uci.h"
 #include "uci_internal.h"
 
+#ifndef MAX_PATH
+#define MAX_PATH 4096
+#endif
+
 #define LINEBUF        32
 
 /*
@@ -723,7 +727,7 @@ static void uci_file_commit(struct uci_context *ctx, struct uci_package **packag
        FILE *f1, *f2 = NULL;
        char *volatile name = NULL;
        char *volatile path = NULL;
-       char *filename = NULL;
+       char filename[MAX_PATH] = {0};
        struct stat statbuf;
        volatile bool do_rename = false;
        int fd;
@@ -735,7 +739,7 @@ static void uci_file_commit(struct uci_context *ctx, struct uci_package **packag
                        UCI_THROW(ctx, UCI_ERR_INVAL);
        }
 
-       if ((asprintf(&filename, "%s/.%s.uci-XXXXXX", ctx->confdir, p->e.name) < 0) || !filename)
+       if (snprintf(filename, MAX_PATH, "%s/.%s.uci-XXXXXX", ctx->confdir, p->e.name) < 0)
                UCI_THROW(ctx, UCI_ERR_MEM);
 
        /* open the config file for writing now, so that it is locked */
@@ -808,7 +812,6 @@ done:
                }
                free(path);
        }
-       free(filename);
        if (ctx->err)
                UCI_THROW(ctx, ctx->err);
 }