UBUNTU-CVE-2023-53520: Race Condition

Q: What conditions are needed to trigger the crash?

The issue requires a race in which hci_unregister_dev() frees a Bluetooth hci_dev object while the suspend notifier is still processing that object. The observed crash path occurs during system suspend through hci_suspend_notifier and hci_suspend_sync.

Q: What is the practical impact of successful triggering?

Successful triggering can crash the system. The supplied severity vector indicates local access, high attack complexity, low privileges required, no user interaction, and an availability impact without confidentiality or integrity impact.

Q: Which Ubuntu kernel packages are listed as affected?

The listed packages are ubuntu/linux-riscv, ubuntu/linux-realtime, ubuntu/linux-hwe-edge, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-azure-fde, ubuntu/linux-gke, and ubuntu/linux-gkeop.

Q: How does the fix address the race?

The fix holds a reference to the hci_dev object while it is being processed by the suspend path. This prevents the object from being freed by hci_unregister_dev() while the notifier still accesses it.

Published Oct 1, 2025

Updated

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix hcisuspendsync crash If hciunregisterdev() frees the hcidev object but hcisuspendnotifier may still be accessing it, it can cause the program to crash. Here's the call trace: <4>[102152.653246] Call Trace: <4>[102152.653254] hcisuspendsync+0x109/0x301 [bluetooth] <4>[102152.653259] hcisuspenddev+0x78/0xcd [bluetooth] <4>[102152.653263] hcisuspendnotifier+0x42/0x7a [bluetooth] <4>[102152.653268] notifiercallchain+0x43/0x6b <4>[102152.653271] blockingnotifiercallchain+0x48/0x69 <4>[102152.653273] pmnotifiercallchain+0x22/0x39 <4>[102152.653276] pmsuspend+0x287/0x57c <4>[102152.653278] statestore+0xae/0xe5 <4>[102152.653281] kernfsfopwrite+0x109/0x173 <4>[102152.653284] vfswrite+0x16f/0x1a2 <4>[102152.653287] ? selinuxfilepermission+0xca/0x16f <4>[102152.653289] ? securityfilepermission+0x36/0x109 <4>[102152.653291] vfswrite+0x114/0x21d <4>[102152.653293] x64syswrite+0x7b/0xdb <4>[102152.653296] dosyscall64+0x59/0x194 <4>[102152.653299] entrySYSCALL64afterhwframe+0x5c/0xc1 This patch holds the reference count of the hcidev object while processing it in hcisuspendnotifier to avoid potential crash caused by the race condition.

Affected Software

126 affected componentsFixes available

ubuntu/linux-hwe-edge*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-azure*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.15<5.15.0-1105.112~20.04.1

5.15.0-1105.112~20.04.1

ubuntu/linux-aws-5.8*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.15<5.15.0-1110.119~20.04.1

5.15.0-1110.119~20.04.1

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.15<5.15.0-1106.115~20.04.1

5.15.0-1106.115~20.04.1

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-gkeop*

ubuntu/linux-gkeop-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.15<5.15.0-176.186~20.04.1

5.15.0-176.186~20.04.1

ubuntu/linux-hwe-5.8*

ubuntu/linux-ibm-5.15<5.15.0-1099.102~20.04.1

5.15.0-1099.102~20.04.1

ubuntu/linux-intel-5.13*

ubuntu/linux-intel-iotg-5.15<5.15.0-1100.106~20.04.1

5.15.0-1100.106~20.04.1

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-175.185~20.04.1

5.15.0-175.185~20.04.1

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1057.57~20.04.1

5.15.0-1057.57~20.04.1

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.15<5.15.0-1102.108~20.04.1

5.15.0-1102.108~20.04.1

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.15<5.15.0-1099.103~20.04.1

5.15.0-1099.103~20.04.1

ubuntu/linux-riscv-5.8*

ubuntu/linux<5.15.0-176.186

5.15.0-176.186

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1105.112

5.15.0-1105.112

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-azure<5.15.0-1110.119

5.15.0-1110.119

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-fde<5.15.0-1114.123

5.15.0-1114.123

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp<5.15.0-1105.114

5.15.0-1105.114

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gke<5.15.0-1101.107

5.15.0-1101.107

ubuntu/linux-gkeop<5.15.0-1088.96

5.15.0-1088.96

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-ibm<5.15.0-1099.102

5.15.0-1099.102

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-intel-iotg<5.15.0-1100.106

5.15.0-1100.106

ubuntu/linux-kvm<5.15.0-1097.102

5.15.0-1097.102

ubuntu/linux-lowlatency<5.15.0-175.185

5.15.0-175.185

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-nvidia<5.15.0-1100.101

5.15.0-1100.101

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-tegra<5.15.0-1057.57

5.15.0-1057.57

ubuntu/linux-nvidia-tegra-igx<5.15.0-1046.46

5.15.0-1046.46

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1102.108

5.15.0-1102.108

ubuntu/linux-oracle-6.5*

ubuntu/linux-raspi<5.15.0-1099.102

5.15.0-1099.102

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1070.74

5.15.0-1070.74

ubuntu/linux-bluefield<5.15.0-1089.91

5.15.0-1089.91

ubuntu/linux-intel-iot-realtime<5.15.0-1097.99

5.15.0-1097.99

ubuntu/linux-realtime<5.15.0-1104.113

5.15.0-1104.113

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1105.112+fips1

5.15.0-1105.112+fips1

ubuntu/linux-azure-fips<5.15.0-1110.119+fips1

5.15.0-1110.119+fips1

ubuntu/linux-fips<5.15.0-176.186+fips1

5.15.0-176.186+fips1

ubuntu/linux-gcp-fips<5.15.0-1105.114+fips1

5.15.0-1105.114+fips1

ubuntu/linux-azure-6.11*

ubuntu/linux-gcp-6.11*

ubuntu/linux-hwe-6.11*

ubuntu/linux-intel*

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.8*

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1105.112~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1110.119~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1106.115~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-176.186~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1099.102~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.106~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-175.185~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1057.57~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1102.108~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1099.103~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-176.186
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1105.112
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1110.119
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1114.123
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1105.114
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1101.107
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1088.96
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1099.102
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.106
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1097.102
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-175.185
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1100.101
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1057.57
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1046.46
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1102.108
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1099.102
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1070.74
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1089.91
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1097.99
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1104.113
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1105.112+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1110.119+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-176.186+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1105.114+fips1

Event History

Oct 1, 2025

CVE Published

via OSV·12:15 PM

Data Sourced

via OSV·12:15 PM

DescriptionSeverityAffected Software

Frequently Asked Questions

What conditions are needed to trigger the crash?

The issue requires a race in which hci_unregister_dev() frees a Bluetooth hci_dev object while the suspend notifier is still processing that object. The observed crash path occurs during system suspend through hci_suspend_notifier and hci_suspend_sync.

What is the practical impact of successful triggering?

Successful triggering can crash the system. The supplied severity vector indicates local access, high attack complexity, low privileges required, no user interaction, and an availability impact without confidentiality or integrity impact.

Which Ubuntu kernel packages are listed as affected?

The listed packages are ubuntu/linux-riscv, ubuntu/linux-realtime, ubuntu/linux-hwe-edge, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-azure-fde, ubuntu/linux-gke, and ubuntu/linux-gkeop.

How does the fix address the race?

The fix holds a reference to the hci_dev object while it is being processed by the suspend path. This prevents the object from being freed by hci_unregister_dev() while the notifier still accesses it.

UBUNTU-CVE-2023-53520: Race Condition

Affected Software

Remediation

Event History

Frequently Asked Questions

What conditions are needed to trigger the crash?

What is the practical impact of successful triggering?

Which Ubuntu kernel packages are listed as affected?

How does the fix address the race?

Company

Resources

Contact

Frequently Asked Questions

What conditions are needed to trigger the crash?

What is the practical impact of successful triggering?

Which Ubuntu kernel packages are listed as affected?

How does the fix address the race?