setup.c:verify_non_filename(): don't die unnecessarily while disambiguating

diff --git a/sha1_file.c b/sha1_file.c
index be991ed22acb0c84141474360f345d51ccc594be..1d328c8d61d97314c4fd7f83888b0d30b22ac301 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -33,7 +33,7 @@ const unsigned char null_sha1[20];
 
 static unsigned int sha1_file_open_flag = O_NOATIME;
 
-signed char hexval_table[256] = {
+const signed char hexval_table[256] = {
         -1, -1, -1, -1, -1, -1, -1, -1,                /* 00-07 */
         -1, -1, -1, -1, -1, -1, -1, -1,                /* 08-0f */
         -1, -1, -1, -1, -1, -1, -1, -1,                /* 10-17 */
@@ -352,10 +352,14 @@ static void read_info_alternates(const char * relative_base, int depth)
        char *map;
        size_t mapsz;
        struct stat st;
-       char path[PATH_MAX];
+       const char alt_file_name[] = "info/alternates";
+       /* Given that relative_base is no longer than PATH_MAX,
+          ensure that "path" has enough space to append "/", the
+          file name, "info/alternates", and a trailing NUL.  */
+       char path[PATH_MAX + 1 + sizeof alt_file_name];
        int fd;
 
-       sprintf(path, "%s/info/alternates", relative_base);
+       sprintf(path, "%s/%s", relative_base, alt_file_name);
        fd = open(path, O_RDONLY);
        if (fd < 0)
                return;
@@ -509,7 +513,10 @@ static int check_packed_git_idx(const char *path,  struct packed_git *p)
                 * for offsets larger than 2^31.
                 */
                unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
-               if (idx_size < min_size || idx_size > min_size + (nr - 1)*8) {
+               unsigned long max_size = min_size;
+               if (nr)
+                       max_size += (nr - 1)*8;
+               if (idx_size < min_size || idx_size > max_size) {
                        munmap(idx_map, idx_size);
                        return error("wrong index file size in %s", path);
                }
@@ -811,7 +818,10 @@ void install_packed_git(struct packed_git *pack)
 
 static void prepare_packed_git_one(char *objdir, int local)
 {
-       char path[PATH_MAX];
+       /* Ensure that this buffer is large enough so that we can
+          append "/pack/" without clobbering the stack even if
+          strlen(objdir) were PATH_MAX.  */
+       char path[PATH_MAX + 1 + 4 + 1 + 1];
        int len;
        DIR *dir;
        struct dirent *de;
@@ -833,6 +843,9 @@ static void prepare_packed_git_one(char *objdir, int local)
                if (!has_extension(de->d_name, ".idx"))
                        continue;
 
+               if (len + namelen + 1 > sizeof(path))
+                       continue;
+
                /* Don't reopen a pack we already have. */
                strcpy(path + len, de->d_name);
                for (p = packed_git; p; p = p->next) {