From: Akihiko Odaki <akihiko.odaki@daynix.com>
To: David Woodhouse <dwmw2@infradead.org>,
Paul Durrant <paul@xen.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Richard Henderson <richard.henderson@linaro.org>,
Eduardo Habkost <eduardo@habkost.net>
Cc: qemu-devel@nongnu.org, devel@daynix.com,
Akihiko Odaki <akihiko.odaki@daynix.com>
Subject: [PATCH] hw/xen: Check if len is 0 before memcpy()
Date: Wed, 08 Jan 2025 20:31:46 +0900 [thread overview]
Message-ID: <20250108-xen-v1-1-3f95cd358eed@daynix.com> (raw)
data->data can be NULL when len is 0. Strictly speaking, the behavior
of memcpy() in such a scenario is undefined so UBSan complaints.
Satisfy UBSan by checking if len is 0 before memcpy().
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
hw/i386/kvm/xen_xenstore.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/hw/i386/kvm/xen_xenstore.c b/hw/i386/kvm/xen_xenstore.c
index 59691056670e..17802aa33d20 100644
--- a/hw/i386/kvm/xen_xenstore.c
+++ b/hw/i386/kvm/xen_xenstore.c
@@ -532,6 +532,10 @@ static void xs_read(XenXenstoreState *s, unsigned int req_id,
return;
}
+ if (!len) {
+ return;
+ }
+
memcpy(&rsp_data[rsp->len], data->data, len);
rsp->len += len;
}
---
base-commit: 38d0939b86e2eef6f6a622c6f1f7befda0146595
change-id: 20241227-xen-fb5a15cc0ca7
Best regards,
--
Akihiko Odaki <akihiko.odaki@daynix.com>
next reply other threads:[~2025-01-08 11:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-08 11:31 Akihiko Odaki [this message]
2025-01-08 11:42 ` [PATCH] hw/xen: Check if len is 0 before memcpy() Philippe Mathieu-Daudé
2025-01-08 11:47 ` David Woodhouse
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