[PATCH AUTOSEL 6.6 15/40] kernel: kexec: copy user-array safely

[Sasha Levin]

From: Philipp Stanner <pstanner@xxxxxxxxxx>

[ Upstream commit 569c8d82f95eb5993c84fb61a649a9c4ddd208b3 ]

Currently, there is no overflow-check with memdup_user().

Use the new function memdup_array_user() instead of memdup_user() for
duplicating the user-space array safely.

Suggested-by: David Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx>
Acked-by: Baoquan He <bhe@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Zack Rusin <zackr@xxxxxxxxxx>
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20230920123612.16914-4-pstanner@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 kernel/kexec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 107f355eac101..8f35a5a42af85 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -247,7 +247,7 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
 		((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
 		return -EINVAL;
 
-	ksegments = memdup_user(segments, nr_segments * sizeof(ksegments[0]));
+	ksegments = memdup_array_user(segments, nr_segments, sizeof(ksegments[0]));
 	if (IS_ERR(ksegments))
 		return PTR_ERR(ksegments);
 
-- 
2.42.0