Vulnerability Database

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Total vulnerabilities in the database

CVE-2025-37918 — linux / linux_kernel

NULL Pointer Dereference

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: btusb: avoid NULL pointer dereference in skb_dequeue()

A NULL pointer dereference can occur in skb_dequeue() when processing a QCA firmware crash dump on WCN7851 (0489:e0f3).

[ 93.672166] Bluetooth: hci0: ACL memdump size(589824)

[ 93.672475] BUG: kernel NULL pointer dereference, address: 0000000000000008 [ 93.672517] Workqueue: hci0 hci_devcd_rx [bluetooth] [ 93.672598] RIP: 0010:skb_dequeue+0x50/0x80

The issue stems from handle_dump_pkt_qca() returning 0 even when a dump packet is successfully processed. This is because it incorrectly forwards the return value of hci_devcd_init() (which returns 0 on success). As a result, the caller (btusb_recv_acl_qca() or btusb_recv_evt_qca()) assumes the packet was not handled and passes it to hci_recv_frame(), leading to premature kfree() of the skb.

Later, hci_devcd_rx() attempts to dequeue the same skb from the dump queue, resulting in a NULL pointer dereference.

Fix this by:

  1. Making handle_dump_pkt_qca() return 0 on success and negative errno on failure, consistent with kernel conventions.
  2. Splitting dump packet detection into separate functions for ACL and event packets for better structure and readability.

This ensures dump packets are properly identified and consumed, avoiding double handling and preventing NULL pointer access.

  • Published: May 20, 2025
  • Updated: Nov 18, 2025
  • CVE: CVE-2025-37918
  • Severity: Medium
  • Exploit:
  • CISA KEV:

CVSS v3:

  • Severity: High
  • Score: 8.8
  • AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWEs:

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CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

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