Linux Kernel up to 6.6.89/6.12.27/6.14.5/6.15-rc4 Bluetooth skb_dequeue null pointer dereference

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.6.89/6.12.27/6.14.5/6.15-rc4. Affected by this vulnerability is the function skb_dequeue of the component Bluetooth. Such manipulation leads to null pointer dereference. This vulnerability is documented as CVE-2025-37918. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.89/6.12.27/6.14.5/6.15-rc4. It has been rated as critical. Affected by this issue is the function skb_dequeue of the component Bluetooth. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. CVE summarizes:

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.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-37918 since 04/16/2025. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 242280 (Ubuntu 25.04 : Linux kernel vulnerabilities (USN-7649-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.90, 6.12.28, 6.14.6 or 6.15-rc5 eliminates this vulnerability. Applying the patch 2e8d44ebaa7babdd5c5ab50ca275826e241920d6/b70b41591ec48c78ec6a885e1f57bfc4029e5e13/8563d9fabd8a4b726ba7acab4737c438bf11a059/0317b033abcd1d8dd2798f0e2de5e84543d0bd22 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (242280) and CERT Bund (WID-SEC-2025-1114). Once again VulDB remains the best source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Dell Avamar
• Open Source Linux Kernel
• Dell NetWorker
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.6.30
• 6.6.31
• 6.6.32
• 6.6.33
• 6.6.34
• 6.6.35
• 6.6.36
• 6.6.37
• 6.6.38
• 6.6.39
• 6.6.40
• 6.6.41
• 6.6.42
• 6.6.43
• 6.6.44
• 6.6.45
• 6.6.46
• 6.6.47
• 6.6.48
• 6.6.49
• 6.6.50
• 6.6.51
• 6.6.52
• 6.6.53
• 6.6.54
• 6.6.55
• 6.6.56
• 6.6.57
• 6.6.58
• 6.6.59
• 6.6.60
• 6.6.61
• 6.6.62
• 6.6.63
• 6.6.64
• 6.6.65
• 6.6.66
• 6.6.67
• 6.6.68
• 6.6.69
• 6.6.70
• 6.6.71
• 6.6.72
• 6.6.73
• 6.6.74
• 6.6.75
• 6.6.76
• 6.6.77
• 6.6.78
• 6.6.79
• 6.6.80
• 6.6.81
• 6.6.82
• 6.6.83
• 6.6.84
• 6.6.85
• 6.6.86
• 6.6.87
• 6.6.88
• 6.6.89
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.14.0
• 6.14.1
• 6.14.2
• 6.14.3
• 6.14.4
• 6.14.5
• 6.15-rc1
• 6.15-rc2
• 6.15-rc3
• 6.15-rc4

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

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Entryinfo

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