Commit b53f27e4 authored by Kees Cook's avatar Kees Cook Committed by James Morris
Browse files

string_helpers: add kstrdup_quotable 



Handle allocating and escaping a string safe for logging.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
parent 3c9d6296

include/linux/string_helpers.h

+2 −0
Original line number Diff line number Diff line
@@ -68,4 +68,6 @@ static inline int string_escape_str_any_np(const char *src, char *dst, 
	return string_escape_str(src, dst, sz, ESCAPE_ANY_NP, only);

}



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



#endif

lib/string_helpers.c

+28 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/export.h>

#include <linux/ctype.h>

#include <linux/errno.h>

#include <linux/slab.h>

#include <linux/string.h>

#include <linux/string_helpers.h>
@@ -534,3 +535,30 @@ int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, 
	return p - dst;

}

EXPORT_SYMBOL(string_escape_mem);



/*

 * Return an allocated string that has been escaped of special characters

 * and double quotes, making it safe to log in quotes.

 */

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

{

	size_t slen, dlen;

	char *dst;

	const int flags = ESCAPE_HEX;

	const char esc[] = "\f\n\r\t\v\a\e\\\"";



	if (!src)

		return NULL;

	slen = strlen(src);



	dlen = string_escape_mem(src, slen, NULL, 0, flags, esc);

	dst = kmalloc(dlen + 1, gfp);

	if (!dst)

		return NULL;



	WARN_ON(string_escape_mem(src, slen, dst, dlen, flags, esc) != dlen);

	dst[dlen] = '\0';



	return dst;

}

EXPORT_SYMBOL_GPL(kstrdup_quotable);