diff options
| -rw-r--r-- | archival/unzip.c | 84 |
1 files changed, 53 insertions, 31 deletions
diff --git a/archival/unzip.c b/archival/unzip.c index 44c4a31..21ba172 100644 --- a/archival/unzip.c +++ b/archival/unzip.c @@ -334,6 +334,7 @@ static void unzip_create_leading_dirs(const char *fn) free(name); } +#if ENABLE_FEATURE_UNZIP_CDF static void unzip_extract_symlink(zip_header_t *zip, const char *dst_fn) { char *target; @@ -365,6 +366,7 @@ static void unzip_extract_symlink(zip_header_t *zip, const char *dst_fn) bb_perror_msg_and_die("can't create symlink '%s'", dst_fn); free(target); } +#endif static void unzip_extract(zip_header_t *zip, int dst_fd) { @@ -437,6 +439,19 @@ static void my_fgets80(char *buf80) } } +static int get_lstat_mode(const char *dst_fn) +{ + struct stat stat_buf; + if (lstat(dst_fn, &stat_buf) == -1) { + if (errno != ENOENT) { + bb_perror_msg_and_die("can't stat '%s'", dst_fn); + } + /* File does not exist */ + return -1; + } + return stat_buf.st_mode; +} + int unzip_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int unzip_main(int argc, char **argv) { @@ -459,7 +474,6 @@ int unzip_main(int argc, char **argv) char *base_dir = NULL; int i, opt; char key_buf[80]; /* must match size used by my_fgets80 */ - struct stat stat_buf; /* -q, -l and -v: UnZip 5.52 of 28 February 2005, by Info-ZIP: * @@ -836,11 +850,11 @@ int unzip_main(int argc, char **argv) goto do_extract; } if (last_char_is(dst_fn, '/')) { + int mode; + /* Extract directory */ - if (stat(dst_fn, &stat_buf) == -1) { - if (errno != ENOENT) { - bb_perror_msg_and_die("can't stat '%s'", dst_fn); - } + mode = get_lstat_mode(dst_fn); + if (mode == -1) { /* ENOENT */ if (!quiet) { printf(" creating: %s\n", dst_fn); } @@ -849,7 +863,7 @@ int unzip_main(int argc, char **argv) xfunc_die(); } } else { - if (!S_ISDIR(stat_buf.st_mode)) { + if (!S_ISDIR(mode)) { bb_error_msg_and_die("'%s' exists but is not a %s", dst_fn, "directory"); } @@ -857,30 +871,33 @@ int unzip_main(int argc, char **argv) goto skip_cmpsize; } check_file: - /* Extract file */ - if (lstat(dst_fn, &stat_buf) == -1) { - /* File does not exist */ - if (errno != ENOENT) { - bb_perror_msg_and_die("can't stat '%s'", dst_fn); + /* Does target file already exist? */ + { + int mode = get_lstat_mode(dst_fn); + if (mode == -1) { + /* ENOENT: does not exist */ + goto do_open_and_extract; } - goto do_open_and_extract; - } - /* File already exists */ - if (overwrite == O_NEVER) { - goto skip_cmpsize; - } - if (!S_ISREG(stat_buf.st_mode)) { - /* File is not regular file */ - bb_error_msg_and_die("'%s' exists but is not a %s", - dst_fn, "regular file"); + if (overwrite == O_NEVER) { + goto skip_cmpsize; + } + if (!S_ISREG(mode)) { + fishy: + bb_error_msg_and_die("'%s' exists but is not a %s", + dst_fn, "regular file"); + } + if (overwrite == O_ALWAYS) { + goto do_open_and_extract; + } + printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn); + my_fgets80(key_buf); + /* User input could take a long time. Is it still a regular file? */ + mode = get_lstat_mode(dst_fn); + if (!S_ISREG(mode)) + goto fishy; } - /* File is regular file */ - if (overwrite == O_ALWAYS) - goto do_open_and_extract; - printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn); - my_fgets80(key_buf); -//TODO: redo lstat + ISREG check! user input could have taken a long time! + /* Extract (or skip) it */ switch (key_buf[0]) { case 'A': overwrite = O_ALWAYS; @@ -888,10 +905,15 @@ int unzip_main(int argc, char **argv) do_open_and_extract: unzip_create_leading_dirs(dst_fn); #if ENABLE_FEATURE_UNZIP_CDF - if (!S_ISLNK(file_mode)) - dst_fd = xopen3(dst_fn, O_WRONLY | O_CREAT | O_TRUNC, file_mode); + dst_fd = -1; + if (!S_ISLNK(file_mode)) { + dst_fd = xopen3(dst_fn, + O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW, + file_mode); + } #else - dst_fd = xopen(dst_fn, O_WRONLY | O_CREAT | O_TRUNC); + /* O_NOFOLLOW defends against symlink attacks */ + dst_fd = xopen(dst_fn, O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW); #endif do_extract: if (!quiet) { @@ -901,7 +923,7 @@ int unzip_main(int argc, char **argv) } #if ENABLE_FEATURE_UNZIP_CDF if (S_ISLNK(file_mode)) { - if (dst_fd != STDOUT_FILENO) /* no -p */ + if (dst_fd != STDOUT_FILENO) /* not -p? */ unzip_extract_symlink(&zip, dst_fn); } else #endif |