Linux Kernel up to 6.12.41/6.15.9/6.16.0 Bluetooth hci_discovery_filter_clear null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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6.2$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.12.41/6.15.9/6.16.0. The affected element is the function hci_discovery_filter_clear of the component Bluetooth. Performing a manipulation results in null pointer dereference. This vulnerability is identified as CVE-2025-38593. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.12.41/6.15.9/6.16.0. This affects the function hci_discovery_filter_clear of the component Bluetooth. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as 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. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix double free in 'hci_discovery_filter_clear()' Function 'hci_discovery_filter_clear()' frees 'uuids' array and then sets it to NULL. There is a tiny chance of the following race: 'hci_cmd_sync_work()' 'update_passive_scan_sync()' 'hci_update_passive_scan_sync()' 'hci_discovery_filter_clear()' kfree(uuids); <-------------------------preempted--------------------------------> 'start_service_discovery()' 'hci_discovery_filter_clear()' kfree(uuids); // DOUBLE FREE <-------------------------preempted--------------------------------> uuids = NULL; To fix it let's add locking around 'kfree()' call and NULL pointer assignment. Otherwise the following backtrace fires: [ ] ------------[ cut here ]------------ [ ] kernel BUG at mm/slub.c:547! [ ] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP [ ] CPU: 3 UID: 0 PID: 246 Comm: bluetoothd Tainted: G O 6.12.19-kernel #1 [ ] Tainted: [O]=OOT_MODULE [ ] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ ] pc : __slab_free+0xf8/0x348 [ ] lr : __slab_free+0x48/0x348 ... [ ] Call trace: [ ] __slab_free+0xf8/0x348 [ ] kfree+0x164/0x27c [ ] start_service_discovery+0x1d0/0x2c0 [ ] hci_sock_sendmsg+0x518/0x924 [ ] __sock_sendmsg+0x54/0x60 [ ] sock_write_iter+0x98/0xf8 [ ] do_iter_readv_writev+0xe4/0x1c8 [ ] vfs_writev+0x128/0x2b0 [ ] do_writev+0xfc/0x118 [ ] __arm64_sys_writev+0x20/0x2c [ ] invoke_syscall+0x68/0xf0 [ ] el0_svc_common.constprop.0+0x40/0xe0 [ ] do_el0_svc+0x1c/0x28 [ ] el0_svc+0x30/0xd0 [ ] el0t_64_sync_handler+0x100/0x12c [ ] el0t_64_sync+0x194/0x198 [ ] Code: 8b0002e6 eb17031f 54fffbe1 d503201f (d4210000) [ ] ---[ end trace 0000000000000000 ]---

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-38593 since 04/16/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 270575 (Oracle Linux 10 / 9 : Unbreakable Enterprise kernel (ELSA-2025-20662)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.42, 6.15.10, 6.16.1 or 6.17-rc1 eliminates this vulnerability. Applying the patch 16852eccbdfaf41a666705e3f8be55cf2864c5ca/a351ff6b8ecca4229afaa0d98042bead8de64799/f8069f34c4c976786ded97498012225af87435d7/2935e556850e9c94d7a00adf14d3cd7fe406ac03 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 (270575), EUVD (EUVD-2025-27922) and CERT Bund (WID-SEC-2025-1869). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

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

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.2

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 270575
Nessus Name: Oracle Linux 10 / 9 : Unbreakable Enterprise kernel (ELSA-2025-20662)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.42/6.15.10/6.16.1/6.17-rc1
Patch: 16852eccbdfaf41a666705e3f8be55cf2864c5ca/a351ff6b8ecca4229afaa0d98042bead8de64799/f8069f34c4c976786ded97498012225af87435d7/2935e556850e9c94d7a00adf14d3cd7fe406ac03

Timelineinfo

04/16/2025 CVE reserved
08/19/2025 +125 days Advisory disclosed
08/19/2025 +0 days VulDB entry created
12/15/2025 +118 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-38593 (🔒)
GCVE (CVE): GCVE-0-2025-38593
GCVE (VulDB): GCVE-100-320601
EUVD: 🔒
CERT Bund: WID-SEC-2025-1869 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 08/19/2025 19:28
Updated: 12/15/2025 23:12
Changes: 08/19/2025 19:28 (59), 09/25/2025 04:38 (7), 10/17/2025 09:03 (2), 10/27/2025 01:43 (1), 11/01/2025 14:04 (1), 11/24/2025 12:41 (2), 11/26/2025 19:44 (11), 12/07/2025 01:38 (1), 12/15/2025 23:12 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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