Merge branch 'exec_rm_compat' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc (4d9dec4d) · Commits · 戴 / test

fs/compat.c

+0 −235

Original line number	Diff line number	Diff line
		@@ -1306,241 +1306,6 @@ compat_sys_openat(unsigned int dfd, const char __user *filename, int flags, int
		return do_sys_open(dfd, filename, flags, mode);
		}

		/*
		* compat_count() counts the number of arguments/envelopes. It is basically
		* a copy of count() from fs/exec.c, except that it works with 32 bit argv
		* and envp pointers.
		*/
		static int compat_count(compat_uptr_t __user *argv, int max)
		{
		int i = 0;

		if (argv != NULL) {
		for (;;) {
		compat_uptr_t p;

		if (get_user(p, argv))
		return -EFAULT;
		if (!p)
		break;
		argv++;
		if (i++ >= max)
		return -E2BIG;

		if (fatal_signal_pending(current))
		return -ERESTARTNOHAND;
		cond_resched();
		}
		}
		return i;
		}

		/*
		* compat_copy_strings() is basically a copy of copy_strings() from fs/exec.c
		* except that it works with 32 bit argv and envp pointers.
		*/
		static int compat_copy_strings(int argc, compat_uptr_t __user *argv,
		struct linux_binprm *bprm)
		{
		struct page *kmapped_page = NULL;
		char *kaddr = NULL;
		unsigned long kpos = 0;
		int ret;

		while (argc-- > 0) {
		compat_uptr_t str;
		int len;
		unsigned long pos;

		if (get_user(str, argv+argc) \|\|
		!(len = strnlen_user(compat_ptr(str), MAX_ARG_STRLEN))) {
		ret = -EFAULT;
		goto out;
		}

		if (len > MAX_ARG_STRLEN) {
		ret = -E2BIG;
		goto out;
		}

		/* We're going to work our way backwords. */
		pos = bprm->p;
		str += len;
		bprm->p -= len;

		while (len > 0) {
		int offset, bytes_to_copy;

		if (fatal_signal_pending(current)) {
		ret = -ERESTARTNOHAND;
		goto out;
		}
		cond_resched();

		offset = pos % PAGE_SIZE;
		if (offset == 0)
		offset = PAGE_SIZE;

		bytes_to_copy = offset;
		if (bytes_to_copy > len)
		bytes_to_copy = len;

		offset -= bytes_to_copy;
		pos -= bytes_to_copy;
		str -= bytes_to_copy;
		len -= bytes_to_copy;

		if (!kmapped_page \|\| kpos != (pos & PAGE_MASK)) {
		struct page *page;

		page = get_arg_page(bprm, pos, 1);
		if (!page) {
		ret = -E2BIG;
		goto out;
		}

		if (kmapped_page) {
		flush_kernel_dcache_page(kmapped_page);
		kunmap(kmapped_page);
		put_page(kmapped_page);
		}
		kmapped_page = page;
		kaddr = kmap(kmapped_page);
		kpos = pos & PAGE_MASK;
		flush_cache_page(bprm->vma, kpos,
		page_to_pfn(kmapped_page));
		}
		if (copy_from_user(kaddr+offset, compat_ptr(str),
		bytes_to_copy)) {
		ret = -EFAULT;
		goto out;
		}
		}
		}
		ret = 0;
		out:
		if (kmapped_page) {
		flush_kernel_dcache_page(kmapped_page);
		kunmap(kmapped_page);
		put_page(kmapped_page);
		}
		return ret;
		}

		/*
		* compat_do_execve() is mostly a copy of do_execve(), with the exception
		* that it processes 32 bit argv and envp pointers.
		*/
		int compat_do_execve(char * filename,
		compat_uptr_t __user *argv,
		compat_uptr_t __user *envp,
		struct pt_regs * regs)
		{
		struct linux_binprm *bprm;
		struct file *file;
		struct files_struct *displaced;
		bool clear_in_exec;
		int retval;

		retval = unshare_files(&displaced);
		if (retval)
		goto out_ret;

		retval = -ENOMEM;
		bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
		if (!bprm)
		goto out_files;

		retval = prepare_bprm_creds(bprm);
		if (retval)
		goto out_free;

		retval = check_unsafe_exec(bprm);
		if (retval < 0)
		goto out_free;
		clear_in_exec = retval;
		current->in_execve = 1;

		file = open_exec(filename);
		retval = PTR_ERR(file);
		if (IS_ERR(file))
		goto out_unmark;

		sched_exec();

		bprm->file = file;
		bprm->filename = filename;
		bprm->interp = filename;

		retval = bprm_mm_init(bprm);
		if (retval)
		goto out_file;

		bprm->argc = compat_count(argv, MAX_ARG_STRINGS);
		if ((retval = bprm->argc) < 0)
		goto out;

		bprm->envc = compat_count(envp, MAX_ARG_STRINGS);
		if ((retval = bprm->envc) < 0)
		goto out;

		retval = prepare_binprm(bprm);
		if (retval < 0)
		goto out;

		retval = copy_strings_kernel(1, &bprm->filename, bprm);
		if (retval < 0)
		goto out;

		bprm->exec = bprm->p;
		retval = compat_copy_strings(bprm->envc, envp, bprm);
		if (retval < 0)
		goto out;

		retval = compat_copy_strings(bprm->argc, argv, bprm);
		if (retval < 0)
		goto out;

		retval = search_binary_handler(bprm, regs);
		if (retval < 0)
		goto out;

		/* execve succeeded */
		current->fs->in_exec = 0;
		current->in_execve = 0;
		acct_update_integrals(current);
		free_bprm(bprm);
		if (displaced)
		put_files_struct(displaced);
		return retval;

		out:
		if (bprm->mm) {
		acct_arg_size(bprm, 0);
		mmput(bprm->mm);
		}

		out_file:
		if (bprm->file) {
		allow_write_access(bprm->file);
		fput(bprm->file);
		}

		out_unmark:
		if (clear_in_exec)
		current->fs->in_exec = 0;
		current->in_execve = 0;

		out_free:
		free_bprm(bprm);

		out_files:
		if (displaced)
		reset_files_struct(displaced);
		out_ret:
		return retval;
		}

		#define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t))

		static int poll_select_copy_remaining(struct timespec end_time, void __user p,

fs/exec.c

+100 −25

Original line number	Diff line number	Diff line
		@@ -55,6 +55,7 @@
		#include <linux/fs_struct.h>
		#include <linux/pipe_fs_i.h>
		#include <linux/oom.h>
		#include <linux/compat.h>

		#include <asm/uaccess.h>
		#include <asm/mmu_context.h>
		@@ -166,8 +167,13 @@ out:
		}

		#ifdef CONFIG_MMU

		void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
		/*
		* The nascent bprm->mm is not visible until exec_mmap() but it can
		* use a lot of memory, account these pages in current->mm temporary
		* for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we
		* change the counter back via acct_arg_size(0).
		*/
		static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
		{
		struct mm_struct *mm = current->mm;
		long diff = (long)(pages - bprm->vma_pages);
		@@ -186,7 +192,7 @@ void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
		#endif
		}

		struct page get_arg_page(struct linux_binprm bprm, unsigned long pos,
		static struct page get_arg_page(struct linux_binprm bprm, unsigned long pos,
		int write)
		{
		struct page *page;
		@@ -305,11 +311,11 @@ static bool valid_arg_len(struct linux_binprm *bprm, long len)

		#else

		void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
		static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
		{
		}

		struct page get_arg_page(struct linux_binprm bprm, unsigned long pos,
		static struct page get_arg_page(struct linux_binprm bprm, unsigned long pos,
		int write)
		{
		struct page *page;
		@@ -398,22 +404,56 @@ err:
		return err;
		}

		struct user_arg_ptr {
		#ifdef CONFIG_COMPAT
		bool is_compat;
		#endif
		union {
		const char __user const __user native;
		#ifdef CONFIG_COMPAT
		compat_uptr_t __user *compat;
		#endif
		} ptr;
		};

		static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr)
		{
		const char __user *native;

		#ifdef CONFIG_COMPAT
		if (unlikely(argv.is_compat)) {
		compat_uptr_t compat;

		if (get_user(compat, argv.ptr.compat + nr))
		return ERR_PTR(-EFAULT);

		return compat_ptr(compat);
		}
		#endif

		if (get_user(native, argv.ptr.native + nr))
		return ERR_PTR(-EFAULT);

		return native;
		}

		/*
		* count() counts the number of strings in array ARGV.
		*/
		static int count(const char __user * const __user * argv, int max)
		static int count(struct user_arg_ptr argv, int max)
		{
		int i = 0;

		if (argv != NULL) {
		if (argv.ptr.native != NULL) {
		for (;;) {
		const char __user * p;
		const char __user *p = get_user_arg_ptr(argv, i);

		if (get_user(p, argv))
		return -EFAULT;
		if (!p)
		break;
		argv++;

		if (IS_ERR(p))
		return -EFAULT;

		if (i++ >= max)
		return -E2BIG;

		@@ -430,7 +470,7 @@ static int count(const char __user * const __user * argv, int max)
		* processes's memory to the new process's stack. The call to get_user_pages()
		* ensures the destination page is created and not swapped out.
		*/
		static int copy_strings(int argc, const char __user const __user argv,
		static int copy_strings(int argc, struct user_arg_ptr argv,
		struct linux_binprm *bprm)
		{
		struct page *kmapped_page = NULL;
		@@ -443,16 +483,18 @@ static int copy_strings(int argc, const char __user const __user argv,
		int len;
		unsigned long pos;

		if (get_user(str, argv+argc) \|\|
		!(len = strnlen_user(str, MAX_ARG_STRLEN))) {
		ret = -EFAULT;
		str = get_user_arg_ptr(argv, argc);
		if (IS_ERR(str))
		goto out;

		len = strnlen_user(str, MAX_ARG_STRLEN);
		if (!len)
		goto out;
		}

		if (!valid_arg_len(bprm, len)) {
		ret = -E2BIG;
		if (!valid_arg_len(bprm, len))
		goto out;
		}

		/* We're going to work our way backwords. */
		pos = bprm->p;
		@@ -519,14 +561,19 @@ out:
		/*
		* Like copy_strings, but get argv and its values from kernel memory.
		*/
		int copy_strings_kernel(int argc, const char const argv,
		int copy_strings_kernel(int argc, const char const __argv,
		struct linux_binprm *bprm)
		{
		int r;
		mm_segment_t oldfs = get_fs();
		struct user_arg_ptr argv = {
		.ptr.native = (const char __user const __user )__argv,
		};

		set_fs(KERNEL_DS);
		r = copy_strings(argc, (const char __user const __user )argv, bprm);
		r = copy_strings(argc, argv, bprm);
		set_fs(oldfs);

		return r;
		}
		EXPORT_SYMBOL(copy_strings_kernel);
		@@ -1379,9 +1426,9 @@ EXPORT_SYMBOL(search_binary_handler);
		/*
		* sys_execve() executes a new program.
		*/
		int do_execve(const char * filename,
		const char __user const __user argv,
		const char __user const __user envp,
		static int do_execve_common(const char *filename,
		struct user_arg_ptr argv,
		struct user_arg_ptr envp,
		struct pt_regs *regs)
		{
		struct linux_binprm *bprm;
		@@ -1489,6 +1536,34 @@ out_ret:
		return retval;
		}

		int do_execve(const char *filename,
		const char __user const __user __argv,
		const char __user const __user __envp,
		struct pt_regs *regs)
		{
		struct user_arg_ptr argv = { .ptr.native = __argv };
		struct user_arg_ptr envp = { .ptr.native = __envp };
		return do_execve_common(filename, argv, envp, regs);
		}

		#ifdef CONFIG_COMPAT
		int compat_do_execve(char *filename,
		compat_uptr_t __user *__argv,
		compat_uptr_t __user *__envp,
		struct pt_regs *regs)
		{
		struct user_arg_ptr argv = {
		.is_compat = true,
		.ptr.compat = __argv,
		};
		struct user_arg_ptr envp = {
		.is_compat = true,
		.ptr.compat = __envp,
		};
		return do_execve_common(filename, argv, envp, regs);
		}
		#endif

		void set_binfmt(struct linux_binfmt *new)
		{
		struct mm_struct *mm = current->mm;

include/linux/binfmts.h

+0 −4

Original line number	Diff line number	Diff line
		@@ -60,10 +60,6 @@ struct linux_binprm {
		unsigned long loader, exec;
		};

		extern void acct_arg_size(struct linux_binprm *bprm, unsigned long pages);
		extern struct page get_arg_page(struct linux_binprm bprm, unsigned long pos,
		int write);

		#define BINPRM_FLAGS_ENFORCE_NONDUMP_BIT 0
		#define BINPRM_FLAGS_ENFORCE_NONDUMP (1 << BINPRM_FLAGS_ENFORCE_NONDUMP_BIT)

Admin message