Clean up uses of "(size_t)-1" in favor of SIZE_MAX.
Cc: linux-hardening@vger.kernel.org
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
include/linux/fortify-string.h | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index 07d5d1921eff..8f2b6b1cb848 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -17,9 +17,9 @@ void __write_overflow_field(size_t avail, size_t wanted) __compiletime_warning("
#define __compiletime_strlen(p) \
({ \
unsigned char *__p = (unsigned char *)(p); \
- size_t __ret = (size_t)-1; \
+ size_t __ret = SIZE_MAX; \
size_t __p_size = __builtin_object_size(p, 1); \
- if (__p_size != (size_t)-1 && \
+ if (__p_size != SIZE_MAX && \
__builtin_constant_p(*__p)) { \
size_t __p_len = __p_size - 1; \
if (__builtin_constant_p(__p[__p_len]) && \
@@ -125,7 +125,7 @@ char *strcat(char * const POS p, const char *q)
{
size_t p_size = __builtin_object_size(p, 1);
- if (p_size == (size_t)-1)
+ if (p_size == SIZE_MAX)
return __underlying_strcat(p, q);
if (strlcat(p, q, p_size) >= p_size)
fortify_panic(__func__);
@@ -140,7 +140,7 @@ __FORTIFY_INLINE __kernel_size_t strnlen(const char * const POS p, __kernel_size
size_t ret;
/* We can take compile-time actions when maxlen is const. */
- if (__builtin_constant_p(maxlen) && p_len != (size_t)-1) {
+ if (__builtin_constant_p(maxlen) && p_len != SIZE_MAX) {
/* If p is const, we can use its compile-time-known len. */
if (maxlen >= p_size)
return p_len;
@@ -168,7 +168,7 @@ __kernel_size_t __fortify_strlen(const char * const POS p)
size_t p_size = __builtin_object_size(p, 1);
/* Give up if we don't know how large p is. */
- if (p_size == (size_t)-1)
+ if (p_size == SIZE_MAX)
return __underlying_strlen(p);
ret = strnlen(p, p_size);
if (p_size <= ret)
@@ -185,7 +185,7 @@ __FORTIFY_INLINE size_t strlcpy(char * const POS p, const char * const POS q, si
size_t q_len; /* Full count of source string length. */
size_t len; /* Count of characters going into destination. */
- if (p_size == (size_t)-1 && q_size == (size_t)-1)
+ if (p_size == SIZE_MAX && q_size == SIZE_MAX)
return __real_strlcpy(p, q, size);
q_len = strlen(q);
len = (q_len >= size) ? size - 1 : q_len;
@@ -213,7 +213,7 @@ __FORTIFY_INLINE ssize_t strscpy(char * const POS p, const char * const POS q, s
size_t q_size = __builtin_object_size(q, 1);
/* If we cannot get size of p and q default to call strscpy. */
- if (p_size == (size_t) -1 && q_size == (size_t) -1)
+ if (p_size == SIZE_MAX && q_size == SIZE_MAX)
return __real_strscpy(p, q, size);
/*
@@ -258,7 +258,7 @@ char *strncat(char * const POS p, const char * const POS q, __kernel_size_t coun
size_t p_size = __builtin_object_size(p, 1);
size_t q_size = __builtin_object_size(q, 1);
- if (p_size == (size_t)-1 && q_size == (size_t)-1)
+ if (p_size == SIZE_MAX && q_size == SIZE_MAX)
return __underlying_strncat(p, q, count);
p_len = strlen(p);
copy_len = strnlen(q, count);
@@ -299,10 +299,10 @@ __FORTIFY_INLINE void fortify_memset_chk(__kernel_size_t size,
/*
* Always stop accesses beyond the struct that contains the
* field, when the buffer's remaining size is known.
- * (The -1 test is to optimize away checks where the buffer
+ * (The SIZE_MAX test is to optimize away checks where the buffer
* lengths are unknown.)
*/
- if (p_size != (size_t)(-1) && p_size < size)
+ if (p_size != SIZE_MAX && p_size < size)
fortify_panic("memset");
}
@@ -393,11 +393,11 @@ __FORTIFY_INLINE void fortify_memcpy_chk(__kernel_size_t size,
/*
* Always stop accesses beyond the struct that contains the
* field, when the buffer's remaining size is known.
- * (The -1 test is to optimize away checks where the buffer
+ * (The SIZE_MAX test is to optimize away checks where the buffer
* lengths are unknown.)
*/
- if ((p_size != (size_t)(-1) && p_size < size) ||
- (q_size != (size_t)(-1) && q_size < size))
+ if ((p_size != SIZE_MAX && p_size < size) ||
+ (q_size != SIZE_MAX && q_size < size))
fortify_panic(func);
}
@@ -496,7 +496,7 @@ char *strcpy(char * const POS p, const char * const POS q)
size_t size;
/* If neither buffer size is known, immediately give up. */
- if (p_size == (size_t)-1 && q_size == (size_t)-1)
+ if (p_size == SIZE_MAX && q_size == SIZE_MAX)
return __underlying_strcpy(p, q);
size = strlen(q) + 1;
/* Compile-time check for const size overflow. */
--
2.34.1Hi Kees,
I love your patch! Yet something to improve:
[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master kees/for-next/pstore v6.0-rc3 next-20220901]
[cannot apply to kees/for-next/hardening]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Kees-Cook/Fix-FORTIFY-y-UBSAN_LOCAL_BOUNDS-y/20220903-044622
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
config: powerpc-allyesconfig (https://download.01.org/0day-ci/archive/20220903/202209030625.wdoOhjAW-lkp@intel.com/config)
compiler: powerpc-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/6c991b3511a531e44e856fdf2b64020b70fd7b22
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Kees-Cook/Fix-FORTIFY-y-UBSAN_LOCAL_BOUNDS-y/20220903-044622
git checkout 6c991b3511a531e44e856fdf2b64020b70fd7b22
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=powerpc prepare
If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>
All errors (new ones prefixed by >>):
scripts/genksyms/parse.y: warning: 9 shift/reduce conflicts [-Wconflicts-sr]
scripts/genksyms/parse.y: warning: 5 reduce/reduce conflicts [-Wconflicts-rr]
scripts/genksyms/parse.y: note: rerun with option '-Wcounterexamples' to generate conflict counterexamples
In file included from include/linux/string.h:253,
from include/linux/uuid.h:12,
from include/linux/mod_devicetable.h:13,
from scripts/mod/devicetable-offsets.c:3:
include/linux/fortify-string.h: In function 'strcat':
>> include/linux/fortify-string.h:98:23: error: 'SIZE_MAX' undeclared (first use in this function)
98 | if (p_size == SIZE_MAX)
| ^~~~~~~~
include/linux/fortify-string.h:6:1: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
5 | #include <linux/const.h>
+++ |+#include <stdint.h>
6 |
include/linux/fortify-string.h:98:23: note: each undeclared identifier is reported only once for each function it appears in
98 | if (p_size == SIZE_MAX)
| ^~~~~~~~
include/linux/fortify-string.h: In function 'strnlen':
include/linux/fortify-string.h:20:24: error: 'SIZE_MAX' undeclared (first use in this function)
20 | size_t __ret = SIZE_MAX; \
| ^~~~~~~~
include/linux/fortify-string.h:109:24: note: in expansion of macro '__compiletime_strlen'
109 | size_t p_len = __compiletime_strlen(p);
| ^~~~~~~~~~~~~~~~~~~~
include/linux/fortify-string.h:20:24: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
20 | size_t __ret = SIZE_MAX; \
| ^~~~~~~~
include/linux/fortify-string.h:109:24: note: in expansion of macro '__compiletime_strlen'
109 | size_t p_len = __compiletime_strlen(p);
| ^~~~~~~~~~~~~~~~~~~~
include/linux/fortify-string.h: In function '__fortify_strlen':
include/linux/fortify-string.h:141:23: error: 'SIZE_MAX' undeclared (first use in this function)
141 | if (p_size == SIZE_MAX)
| ^~~~~~~~
include/linux/fortify-string.h:141:23: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
include/linux/fortify-string.h: In function 'strlcpy':
include/linux/fortify-string.h:158:23: error: 'SIZE_MAX' undeclared (first use in this function)
158 | if (p_size == SIZE_MAX && q_size == SIZE_MAX)
| ^~~~~~~~
include/linux/fortify-string.h:158:23: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
include/linux/fortify-string.h: In function 'strscpy':
include/linux/fortify-string.h:186:23: error: 'SIZE_MAX' undeclared (first use in this function)
186 | if (p_size == SIZE_MAX && q_size == SIZE_MAX)
| ^~~~~~~~
include/linux/fortify-string.h:186:23: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
include/linux/fortify-string.h: In function 'strncat':
include/linux/fortify-string.h:231:23: error: 'SIZE_MAX' undeclared (first use in this function)
231 | if (p_size == SIZE_MAX && q_size == SIZE_MAX)
| ^~~~~~~~
include/linux/fortify-string.h:231:23: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
include/linux/fortify-string.h: In function 'fortify_memset_chk':
include/linux/fortify-string.h:275:23: error: 'SIZE_MAX' undeclared (first use in this function)
275 | if (p_size != SIZE_MAX && p_size < size)
| ^~~~~~~~
include/linux/fortify-string.h:275:23: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
include/linux/fortify-string.h: In function 'fortify_memcpy_chk':
include/linux/fortify-string.h:369:24: error: 'SIZE_MAX' undeclared (first use in this function)
369 | if ((p_size != SIZE_MAX && p_size < size) ||
| ^~~~~~~~
include/linux/fortify-string.h:369:24: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
include/linux/fortify-string.h: In function 'strcpy':
include/linux/fortify-string.h:469:23: error: 'SIZE_MAX' undeclared (first use in this function)
469 | if (p_size == SIZE_MAX && q_size == SIZE_MAX)
| ^~~~~~~~
include/linux/fortify-string.h:469:23: note: 'SIZE_MAX' is defined in header '<stdint.h>'; did you forget to '#include <stdint.h>'?
make[2]: *** [scripts/Makefile.build:117: scripts/mod/devicetable-offsets.s] Error 1
make[2]: Target '__build' not remade because of errors.
make[1]: *** [Makefile:1204: prepare0] Error 2
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:222: __sub-make] Error 2
make: Target 'prepare' not remade because of errors.
vim +/SIZE_MAX +98 include/linux/fortify-string.h
92
93 __FORTIFY_INLINE __diagnose_as(__builtin_strcat, 1, 2)
94 char *strcat(char * const POS p, const char *q)
95 {
96 size_t p_size = __builtin_object_size(p, 1);
97
> 98 if (p_size == SIZE_MAX)
99 return __underlying_strcat(p, q);
100 if (strlcat(p, q, p_size) >= p_size)
101 fortify_panic(__func__);
102 return p;
103 }
104
--
0-DAY CI Kernel Test Service
https://01.org/lkp
On Fri, Sep 02, 2022 at 01:43:51PM -0700, Kees Cook wrote: > Clean up uses of "(size_t)-1" in favor of SIZE_MAX. > > Cc: linux-hardening@vger.kernel.org > Suggested-by: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Kees Cook <keescook@chromium.org> > --- > include/linux/fortify-string.h | 28 ++++++++++++++-------------- > 1 file changed, 14 insertions(+), 14 deletions(-) *brown paper bag* This needs: #include <linux/limits.h> I will fix it locally... -- Kees Cook
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