From 079a028d6327e68cfa5d38b36123637b321c19a7 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 23 Mar 2026 01:27:25 +0000 Subject: string: Remove strncpy() from the kernel strncpy() has been a persistent source of bugs due to its ambiguous intended usage and frequently counter-intuitive semantics: it may not NUL-terminate the destination, and it unconditionally zero-pads to the full length, which isn't always needed. All former callers have been migrated[1] to: - strscpy() for NUL-terminated destinations - strscpy_pad() for NUL-terminated destinations needing zero-padding - strtomem_pad() for non-NUL-terminated fixed-width fields - memcpy_and_pad() for bounded copies with explicit padding - memcpy() for known-length copies Remove the generic implementation, its declaration, the FORTIFY_SOURCE wrapper, and associated tests. Link: https://github.com/KSPP/linux/issues/90 [1] Signed-off-by: Kees Cook --- lib/string.c | 16 ---------------- 1 file changed, 16 deletions(-) (limited to 'lib/string.c') diff --git a/lib/string.c b/lib/string.c index b632c71df1a5..45ca1cfe0184 100644 --- a/lib/string.c +++ b/lib/string.c @@ -88,22 +88,6 @@ char *strcpy(char *dest, const char *src) EXPORT_SYMBOL(strcpy); #endif -#ifndef __HAVE_ARCH_STRNCPY -char *strncpy(char *dest, const char *src, size_t count) -{ - char *tmp = dest; - - while (count) { - if ((*tmp = *src) != 0) - src++; - tmp++; - count--; - } - return dest; -} -EXPORT_SYMBOL(strncpy); -#endif - #ifdef __BIG_ENDIAN # define ALLBUTLAST_BYTE_MASK (~255ul) #else -- cgit v1.2.3