mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-27 12:57:53 +00:00
Code Issues Releases Wiki Activity

fortify: strcat: Move definition to use fortified strlcat()

Browse source 
Move the definition of fortified strcat() to after strlcat() to use it
for bounds checking.

Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook 2023-04-04 14:24:27 -07:00
parent 605395cd7c
commit 55c84a5cf2
1 changed files with 26 additions and 27 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

53
include/linux/fortify-string.h
View file

@ -151,33 +151,6 @@ char *strncpy(char * const POS p, const char *q, __kernel_size_t size)
return __underlying_strncpy(p, q, size);
}
/**
* strcat - Append a string to an existing string
*
* @p: pointer to NUL-terminated string to append to
* @q: pointer to NUL-terminated source string to append from
*
* Do not use this function. While FORTIFY_SOURCE tries to avoid
* read and write overflows, this is only possible when the
* destination buffer size is known to the compiler. Prefer
* building the string with formatting, via scnprintf() or similar.
* At the very least, use strncat().
*
* Returns @p.
*
*/
__FORTIFY_INLINE __diagnose_as(__builtin_strcat, 1, 2)
char *strcat(char * const POS p, const char *q)
{
const size_t p_size = __member_size(p);
if (p_size == SIZE_MAX)
return __underlying_strcat(p, q);
if (strlcat(p, q, p_size) >= p_size)
fortify_panic(__func__);
return p;
}
extern __kernel_size_t __real_strnlen(const char *, __kernel_size_t) __RENAME(strnlen);
/**
* strnlen - Return bounded count of characters in a NUL-terminated string
@ -435,6 +408,32 @@ size_t strlcat(char * const POS p, const char * const POS q, size_t avail)
return wanted;
}
/* Defined after fortified strlcat() to reuse it. */
/**
* strcat - Append a string to an existing string
*
* @p: pointer to NUL-terminated string to append to
* @q: pointer to NUL-terminated source string to append from
*
* Do not use this function. While FORTIFY_SOURCE tries to avoid
* read and write overflows, this is only possible when the
* destination buffer size is known to the compiler. Prefer
* building the string with formatting, via scnprintf() or similar.
* At the very least, use strncat().
*
* Returns @p.
*
*/
__FORTIFY_INLINE __diagnose_as(__builtin_strcat, 1, 2)
char *strcat(char * const POS p, const char *q)
{
const size_t p_size = __member_size(p);
if (strlcat(p, q, p_size) >= p_size)
fortify_panic(__func__);
return p;
}
/**
* strncat - Append a string to an existing string
*