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886d7de631
Merge yet more updates from Andrew Morton: - More MM work. 100ish more to go. Mike Rapoport's "mm: remove __ARCH_HAS_5LEVEL_HACK" series should fix the current ppc issue - Various other little subsystems * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits) lib/ubsan.c: fix gcc-10 warnings tools/testing/selftests/vm: remove duplicate headers selftests: vm: pkeys: fix multilib builds for x86 selftests: vm: pkeys: use the correct page size on powerpc selftests/vm/pkeys: override access right definitions on powerpc selftests/vm/pkeys: test correct behaviour of pkey-0 selftests/vm/pkeys: introduce a sub-page allocator selftests/vm/pkeys: detect write violation on a mapped access-denied-key page selftests/vm/pkeys: associate key on a mapped page and detect write violation selftests/vm/pkeys: associate key on a mapped page and detect access violation selftests/vm/pkeys: improve checks to determine pkey support selftests/vm/pkeys: fix assertion in test_pkey_alloc_exhaust() selftests/vm/pkeys: fix number of reserved powerpc pkeys selftests/vm/pkeys: introduce powerpc support selftests/vm/pkeys: introduce generic pkey abstractions selftests: vm: pkeys: use the correct huge page size selftests/vm/pkeys: fix alloc_random_pkey() to make it really random selftests/vm/pkeys: fix assertion in pkey_disable_set/clear() selftests/vm/pkeys: fix pkey_disable_clear() selftests: vm: pkeys: add helpers for pkey bits ...
159 lines
4.2 KiB
C
159 lines
4.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/fs/binfmt_script.c
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*
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* Copyright (C) 1996 Martin von Löwis
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* original #!-checking implemented by tytso.
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*/
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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#include <linux/binfmts.h>
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#include <linux/init.h>
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#include <linux/file.h>
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#include <linux/err.h>
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#include <linux/fs.h>
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static inline bool spacetab(char c) { return c == ' ' || c == '\t'; }
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static inline const char *next_non_spacetab(const char *first, const char *last)
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{
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for (; first <= last; first++)
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if (!spacetab(*first))
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return first;
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return NULL;
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}
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static inline const char *next_terminator(const char *first, const char *last)
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{
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for (; first <= last; first++)
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if (spacetab(*first) || !*first)
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return first;
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return NULL;
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}
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static int load_script(struct linux_binprm *bprm)
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{
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const char *i_name, *i_sep, *i_arg, *i_end, *buf_end;
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struct file *file;
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int retval;
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/* Not ours to exec if we don't start with "#!". */
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if ((bprm->buf[0] != '#') || (bprm->buf[1] != '!'))
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return -ENOEXEC;
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/*
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* This section handles parsing the #! line into separate
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* interpreter path and argument strings. We must be careful
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* because bprm->buf is not yet guaranteed to be NUL-terminated
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* (though the buffer will have trailing NUL padding when the
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* file size was smaller than the buffer size).
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*
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* We do not want to exec a truncated interpreter path, so either
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* we find a newline (which indicates nothing is truncated), or
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* we find a space/tab/NUL after the interpreter path (which
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* itself may be preceded by spaces/tabs). Truncating the
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* arguments is fine: the interpreter can re-read the script to
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* parse them on its own.
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*/
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buf_end = bprm->buf + sizeof(bprm->buf) - 1;
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i_end = strnchr(bprm->buf, sizeof(bprm->buf), '\n');
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if (!i_end) {
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i_end = next_non_spacetab(bprm->buf + 2, buf_end);
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if (!i_end)
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return -ENOEXEC; /* Entire buf is spaces/tabs */
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/*
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* If there is no later space/tab/NUL we must assume the
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* interpreter path is truncated.
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*/
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if (!next_terminator(i_end, buf_end))
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return -ENOEXEC;
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i_end = buf_end;
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}
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/* Trim any trailing spaces/tabs from i_end */
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while (spacetab(i_end[-1]))
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i_end--;
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/* Skip over leading spaces/tabs */
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i_name = next_non_spacetab(bprm->buf+2, i_end);
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if (!i_name || (i_name == i_end))
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return -ENOEXEC; /* No interpreter name found */
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/* Is there an optional argument? */
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i_arg = NULL;
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i_sep = next_terminator(i_name, i_end);
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if (i_sep && (*i_sep != '\0'))
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i_arg = next_non_spacetab(i_sep, i_end);
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/*
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* If the script filename will be inaccessible after exec, typically
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* because it is a "/dev/fd/<fd>/.." path against an O_CLOEXEC fd, give
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* up now (on the assumption that the interpreter will want to load
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* this file).
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*/
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if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
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return -ENOENT;
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/*
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* OK, we've parsed out the interpreter name and
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* (optional) argument.
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* Splice in (1) the interpreter's name for argv[0]
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* (2) (optional) argument to interpreter
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* (3) filename of shell script (replace argv[0])
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*
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* This is done in reverse order, because of how the
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* user environment and arguments are stored.
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*/
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retval = remove_arg_zero(bprm);
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if (retval)
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return retval;
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retval = copy_string_kernel(bprm->interp, bprm);
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if (retval < 0)
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return retval;
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bprm->argc++;
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*((char *)i_end) = '\0';
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if (i_arg) {
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*((char *)i_sep) = '\0';
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retval = copy_string_kernel(i_arg, bprm);
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if (retval < 0)
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return retval;
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bprm->argc++;
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}
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retval = copy_string_kernel(i_name, bprm);
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if (retval)
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return retval;
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bprm->argc++;
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retval = bprm_change_interp(i_name, bprm);
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if (retval < 0)
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return retval;
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/*
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* OK, now restart the process with the interpreter's dentry.
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*/
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file = open_exec(i_name);
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if (IS_ERR(file))
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return PTR_ERR(file);
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bprm->interpreter = file;
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return 0;
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}
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static struct linux_binfmt script_format = {
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.module = THIS_MODULE,
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.load_binary = load_script,
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};
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static int __init init_script_binfmt(void)
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{
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register_binfmt(&script_format);
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return 0;
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}
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static void __exit exit_script_binfmt(void)
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{
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unregister_binfmt(&script_format);
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}
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core_initcall(init_script_binfmt);
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module_exit(exit_script_binfmt);
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MODULE_LICENSE("GPL");
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