[PATCH 31/43] kmsan: disable strscpy() optimization under KMSAN
STALE1652d
From: Alexander Potapenko <glider@google.com>
Date: 2021-12-14 16:24:00
Also in:
linux-mm, lkml
Subsystem:
generic string library, library code, the rest · Maintainers:
Kees Cook, Andrew Morton, Linus Torvalds
Revision v1 of 10 in this series.
Revisions (10)
Disable the efficient 8-byte reading under KMSAN to avoid false positives. Signed-off-by: Alexander Potapenko <glider@google.com> --- Link: https://linux-review.googlesource.com/id/Iffd8336965e88fce915db2e6a9d6524422975f69 --- lib/string.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/lib/string.c b/lib/string.c
index 485777c9da832..4ece4c7e7831b 100644
--- a/lib/string.c
+++ b/lib/string.c@@ -197,6 +197,14 @@ ssize_t strscpy(char *dest, const char *src, size_t count) max = 0; #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. + */ + if (IS_ENABLED(CONFIG_KMSAN)) + max = 0; + while (max >= sizeof(unsigned long)) { unsigned long c, data;
--
2.34.1.173.g76aa8bc2d0-goog