diff mbox series

[v4,1/3] kasan: move checks to do_strncpy_from_user

Message ID 20241016131802.3115788-2-snovitoll@gmail.com (mailing list archive)
State New
Headers show
Series kasan: migrate the last module test to kunit | expand

Commit Message

Sabyrzhan Tasbolatov Oct. 16, 2024, 1:18 p.m. UTC 
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@gmail.com>
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
---
 lib/strncpy_from_user.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index 989a12a6787..6dc234913dd 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -120,6 +120,9 @@  long strncpy_from_user(char *dst, const char __user *src, long count)
 	if (unlikely(count <= 0))
 		return 0;
 
+	kasan_check_write(dst, count);
+	check_object_size(dst, count, false);
+
 	if (can_do_masked_user_access()) {
 		long retval;
 
@@ -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();