mirror of
https://github.com/torvalds/linux.git
synced 2024-12-06 11:01:43 +00:00
09c434b8a0
Add SPDX license identifiers to all files which: - Have no license information of any form - Have MODULE_LICENCE("GPL*") inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
171 lines
4.4 KiB
C
171 lines
4.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* linux/fs/binfmt_script.c
|
|
*
|
|
* Copyright (C) 1996 Martin von Löwis
|
|
* original #!-checking implemented by tytso.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/string.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/binfmts.h>
|
|
#include <linux/init.h>
|
|
#include <linux/file.h>
|
|
#include <linux/err.h>
|
|
#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)
|
|
{
|
|
for (; first <= last; first++)
|
|
if (!spacetab(*first))
|
|
return first;
|
|
return NULL;
|
|
}
|
|
static inline char *next_terminator(char *first, const char *last)
|
|
{
|
|
for (; first <= last; first++)
|
|
if (spacetab(*first) || !*first)
|
|
return first;
|
|
return NULL;
|
|
}
|
|
|
|
static int load_script(struct linux_binprm *bprm)
|
|
{
|
|
const char *i_arg, *i_name;
|
|
char *cp, *buf_end;
|
|
struct file *file;
|
|
int retval;
|
|
|
|
/* Not ours to exec if we don't start with "#!". */
|
|
if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!'))
|
|
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
|
|
* (though the buffer will have trailing NUL padding when the
|
|
* file size was smaller than the buffer size).
|
|
*
|
|
* We do not want to exec a truncated interpreter path, so either
|
|
* we find a newline (which indicates nothing is truncated), or
|
|
* we find a space/tab/NUL after the interpreter path (which
|
|
* itself may be preceded by spaces/tabs). Truncating the
|
|
* arguments is fine: the interpreter can re-read the script to
|
|
* 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)
|
|
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))
|
|
return -ENOEXEC;
|
|
cp = 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')
|
|
return -ENOEXEC; /* No interpreter name found */
|
|
i_name = cp;
|
|
i_arg = NULL;
|
|
for ( ; *cp && (*cp != ' ') && (*cp != '\t'); cp++)
|
|
/* nothing */ ;
|
|
while ((*cp == ' ') || (*cp == '\t'))
|
|
*cp++ = '\0';
|
|
if (*cp)
|
|
i_arg = cp;
|
|
/*
|
|
* OK, we've parsed out the interpreter name and
|
|
* (optional) argument.
|
|
* Splice in (1) the interpreter's name for argv[0]
|
|
* (2) (optional) argument to interpreter
|
|
* (3) filename of shell script (replace argv[0])
|
|
*
|
|
* This is done in reverse order, because of how the
|
|
* user environment and arguments are stored.
|
|
*/
|
|
retval = remove_arg_zero(bprm);
|
|
if (retval)
|
|
return retval;
|
|
retval = copy_strings_kernel(1, &bprm->interp, bprm);
|
|
if (retval < 0)
|
|
return retval;
|
|
bprm->argc++;
|
|
if (i_arg) {
|
|
retval = copy_strings_kernel(1, &i_arg, bprm);
|
|
if (retval < 0)
|
|
return retval;
|
|
bprm->argc++;
|
|
}
|
|
retval = copy_strings_kernel(1, &i_name, bprm);
|
|
if (retval)
|
|
return retval;
|
|
bprm->argc++;
|
|
retval = bprm_change_interp(i_name, bprm);
|
|
if (retval < 0)
|
|
return retval;
|
|
|
|
/*
|
|
* OK, now restart the process with the interpreter's dentry.
|
|
*/
|
|
file = open_exec(i_name);
|
|
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);
|
|
}
|
|
|
|
static struct linux_binfmt script_format = {
|
|
.module = THIS_MODULE,
|
|
.load_binary = load_script,
|
|
};
|
|
|
|
static int __init init_script_binfmt(void)
|
|
{
|
|
register_binfmt(&script_format);
|
|
return 0;
|
|
}
|
|
|
|
static void __exit exit_script_binfmt(void)
|
|
{
|
|
unregister_binfmt(&script_format);
|
|
}
|
|
|
|
core_initcall(init_script_binfmt);
|
|
module_exit(exit_script_binfmt);
|
|
MODULE_LICENSE("GPL");
|