[PATCH 2/5] kernel: kexec: copy user-array safely

From: Philipp Stanner
Date: Wed Aug 30 2023 - 14:53:45 EST


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>
---
kernel/kexec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 92d301f98776..f6067c1bb089 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -242,7 +242,7 @@ 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);

--
2.41.0