TWxSoftware/twx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

string: Check for "nonstring" attribute on strscpy() arguments

Browse Source 
GCC already checks for arguments that are marked with the "nonstring"[1]
attribute when used on standard C String API functions (e.g. strcpy). Gain
this compile-time checking also for the kernel's primary string copying
function, strscpy().

Note that Clang has neither "nonstring" nor __builtin_has_attribute().

Link: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-nonstring-variable-attribute [1]
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/r/20240805214340.work.339-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
This commit is contained in:
Kees Cook
2024-08-05 14:43:44 -07:00
parent 32ef4b710c
commit 559048d156
3 changed files with 18 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
include/linux/string.h
+8 -4
View File
@@ -76,12 +76,16 @@ ssize_t sized_strscpy(char *, const char *, size_t);
* known size.
*/
#define __strscpy0(dst, src, ...) \
sized_strscpy(dst, src, sizeof(dst) + __must_be_array(dst))
#define __strscpy1(dst, src, size) sized_strscpy(dst, src, size)
sized_strscpy(dst, src, sizeof(dst) + __must_be_array(dst) + \
__must_be_cstr(dst) + __must_be_cstr(src))
#define __strscpy1(dst, src, size) \
sized_strscpy(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src))
#define __strscpy_pad0(dst, src, ...) \
sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst))
#define __strscpy_pad1(dst, src, size) sized_strscpy_pad(dst, src, size)
sized_strscpy_pad(dst, src, sizeof(dst) + __must_be_array(dst) + \
__must_be_cstr(dst) + __must_be_cstr(src))
#define __strscpy_pad1(dst, src, size) \
sized_strscpy_pad(dst, src, size + __must_be_cstr(dst) + __must_be_cstr(src))
/**
* strscpy - Copy a C-string into a sized buffer