Re: [syzbot] Re: [syzbot] [bluetooth?] KASAN: vmalloc-out-of-bounds Read in hci_devcd_dump

syzbot
2025-06-08T18:54:36Z

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: Re: [syzbot] [bluetooth?] KASAN: vmalloc-out-of-bounds Read in hci_devcd_dump
Author: ipravdin.official@gmail.com

#syz test

diff --git a/net/bluetooth/coredump.c b/net/bluetooth/coredump.c
index 819eacb38762..720cb79adf96 100644
--- a/net/bluetooth/coredump.c
+++ b/net/bluetooth/coredump.c
@@ -249,15 +249,15 @@ static void hci_devcd_dump(struct hci_dev *hdev)

size = hdev->dump.tail - hdev->dump.head;

- /* Emit a devcoredump with the available data */
- dev_coredumpv(&hdev->dev, hdev->dump.head, size, GFP_KERNEL);
-
/* Send a copy to monitor as a diagnostic packet */
skb = bt_skb_alloc(size, GFP_ATOMIC);
if (skb) {
skb_put_data(skb, hdev->dump.head, size);
hci_recv_diag(hdev, skb);
}
+
+ /* Emit a devcoredump with the available data */
+ dev_coredumpv(&hdev->dev, hdev->dump.head, size, GFP_KERNEL);
}

Ivan Pravdin