diff mbox series

[v3,06/34] kmsan: Fix kmsan_copy_to_user() on arches with overlapping address spaces

Message ID 20231213233605.661251-7-iii@linux.ibm.com (mailing list archive)
State New
Headers show
Series kmsan: Enable on s390 | expand

Commit Message

Ilya Leoshkevich Dec. 13, 2023, 11:24 p.m. UTC 
Comparing pointers with TASK_SIZE does not make sense when kernel and
userspace overlap. Assume that we are handling user memory access in
this case.

Reported-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 mm/kmsan/hooks.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/mm/kmsan/hooks.c b/mm/kmsan/hooks.c
index 5d6e2dee5692..eafc45f937eb 100644
--- a/mm/kmsan/hooks.c
+++ b/mm/kmsan/hooks.c
@@ -267,7 +267,8 @@  void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy,
 		return;
 
 	ua_flags = user_access_save();
-	if ((u64)to < TASK_SIZE) {
+	if (!IS_ENABLED(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE) ||
+	    (u64)to < TASK_SIZE) {
 		/* This is a user memory access, check it. */
 		kmsan_internal_check_memory((void *)from, to_copy - left, to,
 					    REASON_COPY_TO_USER);