CVE-2026-63948: Bluetooth: L2CAP: fix chan ref leak in l2cap_chan_timeout() on !conn
Published Jul 19, 2026
·Updated
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: fix chan ref leak in l2capchantimeout() on !conn
setchantimer() takes a l2capchan reference via l2capchanhold() before scheduling the delayed work. The normal path in l2capchantimeout() drops this reference with l2capchanput() at the end, but the early return when chan->conn is NULL skips the put, leaking the reference.
Add the missing l2capchanput() before the early return.
Affected Software
245 affected componentsFixes available
Linux Kernel
Linux Linux kernel>=4.19.314<4.20
Linux Linux kernel>=5.4.276<5.5
Linux Linux kernel>=5.10.217<5.10.259
Linux Linux kernel>=5.15.159<5.15.210
Linux Linux kernel>=6.1.91<6.1.176
Linux Linux kernel>=6.6.31<6.6.143
Linux Linux kernel>=6.8.10<6.9
Linux Linux kernel>=6.9.1<6.12.93
Linux Linux kernel>=6.13<6.18.35
Linux Linux kernel>=6.19<7.0.12
Linux Linux kernel=6.9
Linux Linux kernel=7.1-rc1
Linux Linux kernel=7.1-rc2
Linux Linux kernel=7.1-rc3
Linux Linux kernel=7.1-rc4
Linux Linux kernel=7.1-rc5
ubuntu/linux-hwe-edge*
ubuntu/linux-aws-5.0*
ubuntu/linux-aws-5.3*
ubuntu/linux-aws-5.4*
ubuntu/linux-azure*
ubuntu/linux-azure-5.3*
ubuntu/linux-azure-5.4*
ubuntu/linux-azure-edge*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.3*
ubuntu/linux-gcp-5.4*
ubuntu/linux-gke-4.15*
ubuntu/linux-gke-5.4*
ubuntu/linux-gkeop-5.4*
ubuntu/linux-hwe*
ubuntu/linux-hwe-5.4*
ubuntu/linux-hwe-edge*
ubuntu/linux-ibm-5.4*
ubuntu/linux-oem*
ubuntu/linux-oracle-5.0*
ubuntu/linux-oracle-5.3*
ubuntu/linux-oracle-5.4*
ubuntu/linux-raspi-5.4*
ubuntu/linux*
ubuntu/linux-aws*
ubuntu/linux-aws-5.11*
ubuntu/linux-aws-5.13*
ubuntu/linux-aws-5.15<5.15.0-1117.124~20.04.1
5.15.0-1117.124~20.04.1
ubuntu/linux-aws-5.8*
ubuntu/linux-azure*
ubuntu/linux-azure-5.11*
ubuntu/linux-azure-5.13*
ubuntu/linux-azure-5.15<5.15.0-1123.132~20.04.1
5.15.0-1123.132~20.04.1
ubuntu/linux-azure-5.8*
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15<5.15.0-1122.131~20.04.1
5.15.0-1122.131~20.04.1
ubuntu/linux-bluefield*
ubuntu/linux-gcp*
ubuntu/linux-gcp-5.11*
ubuntu/linux-gcp-5.13*
ubuntu/linux-gcp-5.15<5.15.0-1118.128~20.04.1
5.15.0-1118.128~20.04.1
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<5.15.0-198.208~20.04.1
5.15.0-198.208~20.04.1
ubuntu/linux-hwe-5.8*
ubuntu/linux-ibm*
ubuntu/linux-ibm-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-intel-5.13*
ubuntu/linux-intel-iotg-5.15<5.15.0-1112.118~20.04.1
5.15.0-1112.118~20.04.1
ubuntu/linux-iot*
ubuntu/linux-kvm*
ubuntu/linux-lowlatency-hwe-5.15<5.15.0-195.205~20.04.1
5.15.0-195.205~20.04.1
ubuntu/linux-nvidia-tegra-5.15*
ubuntu/linux-oem-5.10*
ubuntu/linux-oem-5.13*
ubuntu/linux-oem-5.6*
ubuntu/linux-oracle*
ubuntu/linux-oracle-5.11*
ubuntu/linux-oracle-5.13*
ubuntu/linux-oracle-5.15<5.15.0-1114.120~20.04.1
5.15.0-1114.120~20.04.1
ubuntu/linux-oracle-5.8*
ubuntu/linux-raspi*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.11*
ubuntu/linux-riscv-5.15<5.15.0-1111.115~20.04.1
5.15.0-1111.115~20.04.1
ubuntu/linux-riscv-5.8*
ubuntu/linux-xilinx-zynqmp*
ubuntu/linux-aws-fips*
ubuntu/linux-azure-fips*
ubuntu/linux-fips*
ubuntu/linux-gcp-fips*
ubuntu/linux<5.15.0-198.208
5.15.0-198.208
ubuntu/linux-allwinner-5.19*
ubuntu/linux-aws<5.15.0-1117.124
5.15.0-1117.124
ubuntu/linux-aws-5.19*
ubuntu/linux-aws-6.2*
ubuntu/linux-aws-6.5*
ubuntu/linux-aws-6.8<6.8.0-1066.69~22.04.1
6.8.0-1066.69~22.04.1
ubuntu/linux-azure<5.15.0-1123.132
5.15.0-1123.132
ubuntu/linux-azure-5.19*
ubuntu/linux-azure-6.2*
ubuntu/linux-azure-6.5*
ubuntu/linux-azure-6.8<6.8.0-1070.78~22.04.1
6.8.0-1070.78~22.04.1
ubuntu/linux-azure-fde<5.15.0-1122.131
5.15.0-1122.131
ubuntu/linux-azure-fde-5.19*
ubuntu/linux-azure-fde-6.2*
ubuntu/linux-azure-fde-6.8<6.8.0-1068.75~22.04.1
6.8.0-1068.75~22.04.1
ubuntu/linux-gcp<5.15.0-1118.128
5.15.0-1118.128
ubuntu/linux-gcp-5.19*
ubuntu/linux-gcp-6.2*
ubuntu/linux-gcp-6.5*
ubuntu/linux-gcp-6.8<6.8.0-1070.78~22.04.1
6.8.0-1070.78~22.04.1
ubuntu/linux-gke<5.15.0-1113.119
5.15.0-1113.119
ubuntu/linux-gkeop<5.15.0-1100.108
5.15.0-1100.108
ubuntu/linux-hwe-5.19*
ubuntu/linux-hwe-6.2*
ubuntu/linux-hwe-6.5*
ubuntu/linux-ibm<5.15.0-1111.115
5.15.0-1111.115
ubuntu/linux-ibm-6.8<6.8.0-1066.67~22.04.1
6.8.0-1066.67~22.04.1
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-intel-iotg<5.15.0-1112.118
5.15.0-1112.118
ubuntu/linux-kvm<5.15.0-1109.114
5.15.0-1109.114
ubuntu/linux-lowlatency<5.15.0-195.205
5.15.0-195.205
ubuntu/linux-lowlatency-hwe-5.19*
ubuntu/linux-lowlatency-hwe-6.2*
ubuntu/linux-lowlatency-hwe-6.5*
ubuntu/linux-lowlatency-hwe-6.8<6.8.0-146.146.1~22.04.1
6.8.0-146.146.1~22.04.1
ubuntu/linux-nvidia<5.15.0-1112.113
5.15.0-1112.113
ubuntu/linux-nvidia-6.2*
ubuntu/linux-nvidia-6.5*
ubuntu/linux-nvidia-6.8<6.8.0-1064.67~22.04.1
6.8.0-1064.67~22.04.1
ubuntu/linux-nvidia-tegra*
ubuntu/linux-nvidia-tegra-igx*
ubuntu/linux-oem-5.17*
ubuntu/linux-oem-6.0*
ubuntu/linux-oem-6.1*
ubuntu/linux-oem-6.5*
ubuntu/linux-oracle<5.15.0-1114.120
5.15.0-1114.120
ubuntu/linux-oracle-6.5*
ubuntu/linux-oracle-6.8*
ubuntu/linux-raspi*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-5.19*
ubuntu/linux-riscv-6.5*
ubuntu/linux-riscv-6.8<6.8.0-146.146~22.04.1
6.8.0-146.146~22.04.1
ubuntu/linux-starfive-5.19*
ubuntu/linux-starfive-6.2*
ubuntu/linux-starfive-6.5*
ubuntu/linux-xilinx-zynqmp<5.15.0-1080.84
5.15.0-1080.84
ubuntu/linux-bluefield<5.15.0-1101.103
5.15.0-1101.103
ubuntu/linux-intel-iot-realtime<5.15.0-1109.111
5.15.0-1109.111
ubuntu/linux-realtime<5.15.0-1116.125
5.15.0-1116.125
ubuntu/linux-realtime-6.8<6.8.1-1061.62~22.04.1
6.8.1-1061.62~22.04.1
ubuntu/linux-aws-fips<5.15.0-1117.124+fips1
5.15.0-1117.124+fips1
ubuntu/linux-azure-fips<5.15.0-1123.132+fips1
5.15.0-1123.132+fips1
ubuntu/linux-fips<5.15.0-198.208+fips1
5.15.0-198.208+fips1
ubuntu/linux-gcp-fips<5.15.0-1118.128+fips1
5.15.0-1118.128+fips1
ubuntu/linux<6.8.0-146.146
6.8.0-146.146
ubuntu/linux-aws<6.8.0-1066.69
6.8.0-1066.69
ubuntu/linux-aws-6.14*
ubuntu/linux-aws-6.17*
ubuntu/linux-azure<6.8.0-1070.78
6.8.0-1070.78
ubuntu/linux-azure-6.11*
ubuntu/linux-azure-6.14*
ubuntu/linux-azure-6.17*
ubuntu/linux-azure-7.0<7.0.0-1014.14~24.04.1
7.0.0-1014.14~24.04.1
ubuntu/linux-azure-fde<6.8.0-1068.75
6.8.0-1068.75
ubuntu/linux-azure-fde-6.14*
ubuntu/linux-azure-fde-6.17*
ubuntu/linux-azure-fde-7.0<7.0.0-1013.13~24.04.1
7.0.0-1013.13~24.04.1
ubuntu/linux-azure-nvidia*
ubuntu/linux-azure-nvidia-6.14*
ubuntu/linux-gcp<6.8.0-1070.78
6.8.0-1070.78
ubuntu/linux-gcp-6.11*
ubuntu/linux-gcp-6.14*
ubuntu/linux-gcp-7.0<7.0.0-1011.11~24.04.1
7.0.0-1011.11~24.04.1
ubuntu/linux-gke<6.8.0-1065.73
6.8.0-1065.73
ubuntu/linux-gkeop<6.8.0-1051.55
6.8.0-1051.55
ubuntu/linux-hwe-6.11*
ubuntu/linux-hwe-6.14*
ubuntu/linux-hwe-6.17*
ubuntu/linux-hwe-7.0<7.0.0-28.28~24.04.1
7.0.0-28.28~24.04.1
ubuntu/linux-ibm<6.8.0-1066.67
6.8.0-1066.67
ubuntu/linux-lowlatency<6.8.0-146.146.1
6.8.0-146.146.1
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-nvidia<6.8.0-1064.67
6.8.0-1064.67
ubuntu/linux-nvidia-6.11*
ubuntu/linux-nvidia-6.17*
ubuntu/linux-nvidia-7.0<7.0.0-1016.16~24.04.1
7.0.0-1016.16~24.04.1
ubuntu/linux-nvidia-lowlatency<6.8.0-1064.67.1
6.8.0-1064.67.1
ubuntu/linux-nvidia-tegra<6.8.0-1035.38
6.8.0-1035.38
ubuntu/linux-oem-6.11*
ubuntu/linux-oem-6.14*
ubuntu/linux-oem-6.17*
ubuntu/linux-oem-6.8*
ubuntu/linux-oracle<6.8.0-1063.66
6.8.0-1063.66
ubuntu/linux-oracle-6.14*
ubuntu/linux-oracle-6.17*
ubuntu/linux-oracle-7.0<7.0.0-1011.11~24.04.1
7.0.0-1011.11~24.04.1
ubuntu/linux-raspi*
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-riscv-6.14*
ubuntu/linux-riscv-6.17*
ubuntu/linux-riscv-7.0<7.0.0-28.28.1~24.04.3
7.0.0-28.28.1~24.04.3
ubuntu/linux-xilinx*
ubuntu/linux-bluefield<6.8.0-1032.37
6.8.0-1032.37
ubuntu/linux-raspi-realtime*
ubuntu/linux-realtime<6.8.1-1061.62
6.8.1-1061.62
ubuntu/linux-realtime-6.14*
ubuntu/linux-realtime-6.17*
ubuntu/linux-aws-fips<6.8.0-1066.69+fips1
6.8.0-1066.69+fips1
ubuntu/linux-azure-fips<6.8.0-1069.77+fips1
6.8.0-1069.77+fips1
ubuntu/linux-fips<6.8.0-146.146+fips1
6.8.0-146.146+fips1
ubuntu/linux-gcp-fips<6.8.0-1070.78+fips1
6.8.0-1070.78+fips1
ubuntu/linux<7.0.0-28.28
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ubuntu/linux-aws<7.0.0-1009.9
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ubuntu/linux-azure<7.0.0-1010.10
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ubuntu/linux-azure-fde<7.0.0-1009.9
7.0.0-1009.9
ubuntu/linux-gcp<7.0.0-1008.8
7.0.0-1008.8
ubuntu/linux-gke<7.0.0-1003.4
7.0.0-1003.4
ubuntu/linux-ibm<7.0.0-1010.10
7.0.0-1010.10
ubuntu/linux-nvidia<7.0.0-1016.16
7.0.0-1016.16
ubuntu/linux-nvidia-bos<7.0.0-2016.16
7.0.0-2016.16
ubuntu/linux-oem-7.0<7.0.0-1009.9
7.0.0-1009.9
ubuntu/linux-oracle<7.0.0-1008.8
7.0.0-1008.8
ubuntu/linux-raspi<7.0.0-1015.15
7.0.0-1015.15
ubuntu/linux-realtime<7.0.0-28.28.1
7.0.0-28.28.1
ubuntu/linux-riscv<7.0.0-28.28.1
7.0.0-28.28.1
debian/linux<6.1.176-1
6.1.176-1
debian/linux<6.12.94-1
6.12.94-1
debian/linux<7.0.12-1
7.0.12-1
linux/kernel<5.10.259
5.10.259
linux/kernel>=5.11.0<5.15.210
5.15.210
linux/kernel>=5.16.0<6.1.176
6.1.176
linux/kernel>=6.2.0<6.6.143
6.6.143
linux/kernel>=6.7.0<6.12.93
6.12.93
linux/kernel>=6.9.0<6.18.35
6.18.35
linux/kernel>=6.13.0<7.0.12
7.0.12
debian/linux
6.1.176-16.1.190-16.12.107-16.12.115-27.2.12-17.2.15-1
Remediation
Event History
Jul 19, 2026
CVE Published
via MITRE·02:55 PM
Data Sourced
via MITRE·02:55 PM
Description
Data Sourced
via OSV·02:55 PM
DescriptionAffected Software
Data Sourced
via NVD·04:17 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via OSV·04:17 PM
Severity
Frequently Asked Questions
1
What condition triggers the reference leak?
The leak occurs when l2cap_chan_timeout() runs while chan->conn is NULL. In that early-return path, the reference acquired by __set_chan_timer() is not released.
2
What is the impact described by the fix?
The described impact is a leaked L2CAP channel reference. The provided data does not specify a remote attack vector, privilege requirement, or a concrete consequence such as denial of service.
3
How can I determine whether the issue is fixed in my kernel source?
Inspect l2cap_chan_timeout() for the early-return path handling a NULL chan->conn value. The fixed code calls l2cap_chan_put() before returning from that path.