Commit 21985319 authored by Kees Cook's avatar Kees Cook Committed by James Morris
Browse files

string_helpers: add kstrdup_quotable_file 



Allocate a NULL-terminated file path with special characters escaped,
safe for logging.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
parent 0d044328

include/linux/string_helpers.h

+3 −0
Original line number Diff line number Diff line
@@ -3,6 +3,8 @@ 


#include <linux/types.h>



struct file;



/* Descriptions of the types of units to

 * print in */

enum string_size_units {
@@ -70,5 +72,6 @@ static inline int string_escape_str_any_np(const char *src, char *dst, 


char *kstrdup_quotable(const char *src, gfp_t gfp);

char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp);

char *kstrdup_quotable_file(struct file *file, gfp_t gfp);



#endif

lib/string_helpers.c

+30 −0
Original line number Diff line number Diff line
@@ -10,6 +10,8 @@ 
#include <linux/export.h>

#include <linux/ctype.h>

#include <linux/errno.h>

#include <linux/fs.h>

#include <linux/limits.h>

#include <linux/mm.h>

#include <linux/slab.h>

#include <linux/string.h>
@@ -596,3 +598,31 @@ char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp) 
	return quoted;

}

EXPORT_SYMBOL_GPL(kstrdup_quotable_cmdline);



/*

 * Returns allocated NULL-terminated string containing pathname,

 * with special characters escaped, able to be safely logged. If

 * there is an error, the leading character will be "<".

 */

char *kstrdup_quotable_file(struct file *file, gfp_t gfp)

{

	char *temp, *pathname;



	if (!file)

		return kstrdup("<unknown>", gfp);



	/* We add 11 spaces for ' (deleted)' to be appended */

	temp = kmalloc(PATH_MAX + 11, GFP_TEMPORARY);

	if (!temp)

		return kstrdup("<no_memory>", gfp);



	pathname = file_path(file, temp, PATH_MAX + 11);

	if (IS_ERR(pathname))

		pathname = kstrdup("<too_long>", gfp);

	else

		pathname = kstrdup_quotable(pathname, gfp);



	kfree(temp);

	return pathname;

}

EXPORT_SYMBOL_GPL(kstrdup_quotable_file);