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authorLinus Torvalds <torvalds@linux-foundation.org>2025-04-18 23:20:20 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2025-04-18 23:20:20 +0300
commit3bf8a4598ff32b59248be017bce8d20a4e472c7a (patch)
tree2cafbcd9ae127770f5965b88712a75e56283c2bb /lib/string.c
parent30d451e3734b827d4064f2a77af6de65382860a4 (diff)
parent3f2925174f8bd811f9399cb4049f6b75fd2fba91 (diff)
downloadlinux-3bf8a4598ff32b59248be017bce8d20a4e472c7a.tar.xz
Merge tag 'hardening-v6.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening fixes from Kees Cook: - lib/prime_numbers: KUnit test should not select PRIME_NUMBERS (Geert Uytterhoeven) - ubsan: Fix panic from test_ubsan_out_of_bounds (Mostafa Saleh) - ubsan: Remove 'default UBSAN' from UBSAN_INTEGER_WRAP (Nathan Chancellor) - string: Add load_unaligned_zeropad() code path to sized_strscpy() (Peter Collingbourne) - kasan: Add strscpy() test to trigger tag fault on arm64 (Vincenzo Frascino) - Disable GCC randstruct for COMPILE_TEST * tag 'hardening-v6.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: lib/prime_numbers: KUnit test should not select PRIME_NUMBERS ubsan: Fix panic from test_ubsan_out_of_bounds lib/Kconfig.ubsan: Remove 'default UBSAN' from UBSAN_INTEGER_WRAP hardening: Disable GCC randstruct for COMPILE_TEST kasan: Add strscpy() test to trigger tag fault on arm64 string: Add load_unaligned_zeropad() code path to sized_strscpy()
Diffstat (limited to 'lib/string.c')
-rw-r--r--lib/string.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/lib/string.c b/lib/string.c
index eb4486ed40d2..b632c71df1a5 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -119,6 +119,7 @@ ssize_t sized_strscpy(char *dest, const char *src, size_t count)
if (count == 0 || WARN_ON_ONCE(count > INT_MAX))
return -E2BIG;
+#ifndef CONFIG_DCACHE_WORD_ACCESS
#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
/*
* If src is unaligned, don't cross a page boundary,
@@ -134,11 +135,13 @@ ssize_t sized_strscpy(char *dest, const char *src, size_t count)
if (((long) dest | (long) src) & (sizeof(long) - 1))
max = 0;
#endif
+#endif
/*
- * read_word_at_a_time() below may read uninitialized bytes after the
- * trailing zero and use them in comparisons. Disable this optimization
- * under KMSAN to prevent false positive reports.
+ * load_unaligned_zeropad() or read_word_at_a_time() below may read
+ * uninitialized bytes after the trailing zero and use them in
+ * comparisons. Disable this optimization under KMSAN to prevent
+ * false positive reports.
*/
if (IS_ENABLED(CONFIG_KMSAN))
max = 0;
@@ -146,7 +149,11 @@ ssize_t sized_strscpy(char *dest, const char *src, size_t count)
while (max >= sizeof(unsigned long)) {
unsigned long c, data;
+#ifdef CONFIG_DCACHE_WORD_ACCESS
+ c = load_unaligned_zeropad(src+res);
+#else
c = read_word_at_a_time(src+res);
+#endif
if (has_zero(c, &data, &constants)) {
data = prep_zero_mask(c, data, &constants);
data = create_zero_mask(data);