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authorKees Cook <keescook@chromium.org>2022-09-07 16:27:06 -0700
committerKees Cook <keescook@chromium.org>2022-09-07 16:37:48 -0700
commit66cb2a36a96f6facbcb4ef1db967b8e9ea6910fe (patch)
tree382e1e769ad3e6ad749262f9482d03670004b98a /lib
parent98388bda6a99d76309f81584f2bc0d773bdf8b35 (diff)
kunit/memcpy: Avoid pathological compile-time string size
The memcpy() KUnit tests are trying to sanity-check run-time behaviors, but tripped compile-time warnings about a pathological condition of a too-small buffer being used for input. Avoid this by explicitly resizing the buffer, but leaving the string short. Avoid the following warning: lib/memcpy_kunit.c: In function 'strtomem_test': include/linux/string.h:303:42: warning: 'strnlen' specified bound 4 exceeds source size 3 [-Wstringop-overread] 303 | memcpy(dest, src, min(_dest_len, strnlen(src, _dest_len))); \ include/linux/minmax.h:32:39: note: in definition of macro '__cmp_once' 32 | typeof(y) unique_y = (y); \ | ^ include/linux/minmax.h:45:25: note: in expansion of macro '__careful_cmp' 45 | #define min(x, y) __careful_cmp(x, y, <) | ^~~~~~~~~~~~~ include/linux/string.h:303:27: note: in expansion of macro 'min' 303 | memcpy(dest, src, min(_dest_len, strnlen(src, _dest_len))); \ | ^~~ lib/memcpy_kunit.c:290:9: note: in expansion of macro 'strtomem' 290 | strtomem(wrap.output, input); | ^~~~~~~~ lib/memcpy_kunit.c:275:27: note: source object allocated here 275 | static const char input[] = "hi"; | ^~~~~ Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/linux-mm/202209070728.o3stvgVt-lkp@intel.com Fixes: dfbafa70bde2 ("string: Introduce strtomem() and strtomem_pad()") Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/memcpy_kunit.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/memcpy_kunit.c b/lib/memcpy_kunit.c
index d22fa3838ee9..2b5cc70ac53f 100644
--- a/lib/memcpy_kunit.c
+++ b/lib/memcpy_kunit.c
@@ -272,7 +272,7 @@ static void memset_test(struct kunit *test)
static void strtomem_test(struct kunit *test)
{
- static const char input[] = "hi";
+ static const char input[sizeof(unsigned long)] = "hi";
static const char truncate[] = "this is too long";
struct {
unsigned long canary1;