From: Philipp Stanner <pstanner@redhat.com>
Date: Wed, 20 Sep 2023 12:36:10 +0000 (+0200)
Subject: kernel: kexec: copy user-array safely
X-Git-Tag: v6.5.13~429
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b0ed017a2b9735753eb95798d9f60176480424ca;p=thirdparty%2Fkernel%2Fstable.git

kernel: kexec: copy user-array safely

[ 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@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Zack Rusin <zackr@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230920123612.16914-4-pstanner@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/kernel/kexec.c b/kernel/kexec.c
index 92d301f987766..f6067c1bb0893 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);