Create and use new vmalloc'ed buffer with dev_coredumpv. From dev_coredumpv documentation: `This function takes ownership of the vmalloc'ed data and will free it when it is no longer used.` As hdev->dump is used after dev_coredumpv, create temporary buffer to hold hdev->dump data. Reported-by: syzbot+ac3c79181f6aecc5120c@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://lore.kernel.org/all/67eaa688.050a0220.1547ec.014a.GAE@xxxxxxxxxx Fixes: b257e02ecc46 ("HCI: coredump: Log devcd dumps into the monitor") Signed-off-by: Ivan Pravdin <ipravdin.official@xxxxxxxxx> --- net/bluetooth/coredump.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/coredump.c b/net/bluetooth/coredump.c index 819eacb38762..1232c9a94f95 100644 --- a/net/bluetooth/coredump.c +++ b/net/bluetooth/coredump.c @@ -243,6 +243,7 @@ static void hci_devcd_handle_pkt_pattern(struct hci_dev *hdev, static void hci_devcd_dump(struct hci_dev *hdev) { struct sk_buff *skb; + char *coredump; u32 size; bt_dev_dbg(hdev, "state %d", hdev->dump.state); @@ -250,7 +251,11 @@ 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); + coredump = vmalloc(size); + if (coredump) { + memcpy(coredump, hdev->dump.head, size); + dev_coredumpv(&hdev->dev, coredump, size, GFP_KERNEL); + } /* Send a copy to monitor as a diagnostic packet */ skb = bt_skb_alloc(size, GFP_ATOMIC); -- 2.45.2
