diff options
Diffstat (limited to 'fs/binfmt_script.c')
| -rw-r--r-- | fs/binfmt_script.c | 88 |
1 files changed, 38 insertions, 50 deletions
diff --git a/fs/binfmt_script.c b/fs/binfmt_script.c index e9e6a6f4a35f..1b6625e95958 100644 --- a/fs/binfmt_script.c +++ b/fs/binfmt_script.c @@ -16,14 +16,14 @@ #include <linux/fs.h> static inline bool spacetab(char c) { return c == ' ' || c == '\t'; } -static inline char *next_non_spacetab(char *first, const char *last) +static inline const char *next_non_spacetab(const char *first, const char *last) { for (; first <= last; first++) if (!spacetab(*first)) return first; return NULL; } -static inline char *next_terminator(char *first, const char *last) +static inline const char *next_terminator(const char *first, const char *last) { for (; first <= last; first++) if (spacetab(*first) || !*first) @@ -33,8 +33,7 @@ static inline char *next_terminator(char *first, const char *last) static int load_script(struct linux_binprm *bprm) { - const char *i_arg, *i_name; - char *cp, *buf_end; + const char *i_name, *i_sep, *i_arg, *i_end, *buf_end; struct file *file; int retval; @@ -43,20 +42,6 @@ static int load_script(struct linux_binprm *bprm) return -ENOEXEC; /* - * If the script filename will be inaccessible after exec, typically - * because it is a "/dev/fd/<fd>/.." path against an O_CLOEXEC fd, give - * up now (on the assumption that the interpreter will want to load - * this file). - */ - if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE) - return -ENOENT; - - /* Release since we are not mapping a binary into memory. */ - allow_write_access(bprm->file); - fput(bprm->file); - bprm->file = NULL; - - /* * This section handles parsing the #! line into separate * interpreter path and argument strings. We must be careful * because bprm->buf is not yet guaranteed to be NUL-terminated @@ -71,39 +56,43 @@ static int load_script(struct linux_binprm *bprm) * parse them on its own. */ buf_end = bprm->buf + sizeof(bprm->buf) - 1; - cp = strnchr(bprm->buf, sizeof(bprm->buf), '\n'); - if (!cp) { - cp = next_non_spacetab(bprm->buf + 2, buf_end); - if (!cp) + i_end = strnchr(bprm->buf, sizeof(bprm->buf), '\n'); + if (!i_end) { + i_end = next_non_spacetab(bprm->buf + 2, buf_end); + if (!i_end) return -ENOEXEC; /* Entire buf is spaces/tabs */ /* * If there is no later space/tab/NUL we must assume the * interpreter path is truncated. */ - if (!next_terminator(cp, buf_end)) + if (!next_terminator(i_end, buf_end)) return -ENOEXEC; - cp = buf_end; + i_end = buf_end; } - /* NUL-terminate the buffer and any trailing spaces/tabs. */ - *cp = '\0'; - while (cp > bprm->buf) { - cp--; - if ((*cp == ' ') || (*cp == '\t')) - *cp = '\0'; - else - break; - } - for (cp = bprm->buf+2; (*cp == ' ') || (*cp == '\t'); cp++); - if (*cp == '\0') + /* Trim any trailing spaces/tabs from i_end */ + while (spacetab(i_end[-1])) + i_end--; + + /* Skip over leading spaces/tabs */ + i_name = next_non_spacetab(bprm->buf+2, i_end); + if (!i_name || (i_name == i_end)) return -ENOEXEC; /* No interpreter name found */ - i_name = cp; + + /* Is there an optional argument? */ i_arg = NULL; - for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++) - /* nothing */ ; - while ((*cp == ' ') || (*cp == '\t')) - *cp++ = '\0'; - if (*cp) - i_arg = cp; + i_sep = next_terminator(i_name, i_end); + if (i_sep && (*i_sep != '\0')) + i_arg = next_non_spacetab(i_sep, i_end); + + /* + * If the script filename will be inaccessible after exec, typically + * because it is a "/dev/fd/<fd>/.." path against an O_CLOEXEC fd, give + * up now (on the assumption that the interpreter will want to load + * this file). + */ + if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE) + return -ENOENT; + /* * OK, we've parsed out the interpreter name and * (optional) argument. @@ -117,17 +106,19 @@ static int load_script(struct linux_binprm *bprm) retval = remove_arg_zero(bprm); if (retval) return retval; - retval = copy_strings_kernel(1, &bprm->interp, bprm); + retval = copy_string_kernel(bprm->interp, bprm); if (retval < 0) return retval; bprm->argc++; + *((char *)i_end) = '\0'; if (i_arg) { - retval = copy_strings_kernel(1, &i_arg, bprm); + *((char *)i_sep) = '\0'; + retval = copy_string_kernel(i_arg, bprm); if (retval < 0) return retval; bprm->argc++; } - retval = copy_strings_kernel(1, &i_name, bprm); + retval = copy_string_kernel(i_name, bprm); if (retval) return retval; bprm->argc++; @@ -142,11 +133,8 @@ static int load_script(struct linux_binprm *bprm) if (IS_ERR(file)) return PTR_ERR(file); - bprm->file = file; - retval = prepare_binprm(bprm); - if (retval < 0) - return retval; - return search_binary_handler(bprm); + bprm->interpreter = file; + return 0; } static struct linux_binfmt script_format = { |