Since in the commit 2865baf54077("x86: support user address masking instead
of non-speculative conditional") do_strncpy_from_user() is called from
multiple places, we should sanitize the kernel *dst memory and size
which were done in strncpy_from_user() previously.
Fixes: 2865baf54077 ("x86: support user address masking instead of non-speculative conditional")
Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>
---
lib/strncpy_from_user.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index 989a12a6787..f36ad821176 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -31,6 +31,9 @@ static __always_inline long do_strncpy_from_user(char *dst, const char __user *s
const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
unsigned long res = 0;
+ kasan_check_write(dst, count);
+ check_object_size(dst, count, false);
+
if (IS_UNALIGNED(src, dst))
goto byte_at_a_time;
@@ -142,8 +145,6 @@ long strncpy_from_user(char *dst, const char __user *src, long count)
if (max > count)
max = count;
- kasan_check_write(dst, count);
- check_object_size(dst, count, false);
if (user_read_access_begin(src, max)) {
retval = do_strncpy_from_user(dst, src, count, max);
user_read_access_end();
--
2.34.1
