Description
In the Linux kernel, the following vulnerability has been resolved:
USB: cdc-acm: skip URB restart in port_shutdown if disconnected
acm_port_shutdown() is called from the tty-port machinery whenever the
last user closes the port. acm_disconnect() sets acm->disconnected and
calls tty_port_tty_vhangup(), which eventually triggers port_shutdown().
At that point acm_disconnect() has already called acm_poison_urbs() and
is about to free the control and read URBs.
However, acm_port_shutdown() unconditionally calls acm_unpoison_urbs()
and, when the ALWAYS_POLL_CTRL quirk is set, immediately re-submits the
ctrlurb and all read URBs. If the concurrent acm_disconnect() then
frees those URBs and their DMA buffers while they are in-flight, the
result is a use-after-free in acm_ctrl_irq() or acm_read_bulk_callback()
accessing the freed DMA memory.
Fix by checking acm->disconnected after draining the delayed anchor and
returning early: if we are in a disconnect path the URBs must remain
poisoned and must not be resubmitted.
The early return is placed after the delayed-anchor drain loop because
that loop only cancels write-side accounting (wb->use = false and
autopm counter) and does not touch the hardware path.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.1.175 – < 6.1.191, 6.6.136 – < 6.6.160, 6.12.83 – < 6.12.113, 6.18.24 – < 6.18.56, 6.19.14 – < 6.20, 7.0.1 – < 7.1, 7.1 | 6.1.191 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 7.2.10-1 | — |
| Debian 13 | linux | 6.12.113-1 | — |
| Debian 12 | linux | No fix yet | — |
| Debian 12 | linux-6.12 | 6.12.113-1~deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1036.41 | — |
| Ubuntu 26.04 LTS | linux | 7.0.0-43.43 | USN-9018-1 |
| Ubuntu 26.04 LTS | linux-aws | 7.0.0-1017.18 | USN-9018-1 |
| Ubuntu 26.04 LTS | linux-azure | 7.0.0-1020.21 | USN-9019-1 |
| Ubuntu 26.04 LTS | linux-azure-fde | 7.0.0-1019.19 | USN-9020-1 |
| Ubuntu 26.04 LTS | linux-gcp | 7.0.0-1017.19 | USN-9018-1 |
| Ubuntu 26.04 LTS | linux-gke | 7.0.0-1010.11 | USN-9020-1 |
| Ubuntu 26.04 LTS | linux-ibm +1 | 7.0.0-1018.18 | USN-9018-1 |
| Ubuntu 26.04 LTS | linux-oracle | 7.0.0-1016.18 | USN-9018-1 |
| Ubuntu 26.04 LTS | linux-raspi | 7.0.0-1023.23 | USN-9021-1 |
| Ubuntu 26.04 LTS | linux-realtime | 7.0.0-43.43.1 | USN-9020-1 |
| Ubuntu 26.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-149.149 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1069.74 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-aws-7.0 | 7.0.0-1017.18~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1073.82 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1071.78 | USN-9039-1 |
| Ubuntu 24.04 LTS | linux-azure-fde-7.0 | 7.0.0-1019.19~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1073.81 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-gcp-7.0 | 7.0.0-1017.19~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1068.77 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1053.57 | USN-9023-1 |
| Ubuntu 24.04 LTS | linux-hwe-7.0 | 7.0.0-43.43~24.04.1 | USN-9018-2 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1069.70 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-149.149.1 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1067.70 | USN-9024-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1067.70.1 | USN-9040-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1039.40 | USN-9091-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1067.71 | USN-9022-1 |
| Ubuntu 24.04 LTS | linux-oracle-7.0 | 7.0.0-1016.18~24.04.1 | USN-9020-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1068.72 | USN-9025-1 |
| Ubuntu 24.04 LTS | linux-riscv +29 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-7.0 | 7.0.0-43.43.1~24.04.2 | — |
| Ubuntu 24.04 LTS | linux-vmware | 6.8.0-1010.10 | USN-9022-1 |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1069.74~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1073.82~22.04.1 | USN-9026-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1071.78~22.04.1 | USN-9026-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1073.81~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-149.149~22.04.1 | USN-9066-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1069.70~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-149.149.1~22.04.1 | USN-9024-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1067.71~22.04.1 | USN-9025-1 |
| Ubuntu 22.04 LTS | linux-riscv +33 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-149.149~22.04.2 | — |
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2056.58 | USN-9025-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1064.65 | USN-9023-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1064.65~22.04.1 | USN-9024-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1069.74+fips1 | USN-9023-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1073.82+fips1 | USN-9022-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1073.81+fips1 | USN-9023-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +7 | 6.4.0-150700.53.90.1 | SUSE-SU-2026:5091-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.90.1.150700.17.51.1 | SUSE-SU-2026:5091-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.41.1 | SUSE-SU-2026:24662-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.41.1.160000.2.32 | SUSE-SU-2026:24662-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.41.1 | SUSE-SU-2026:24662-1, SUSE-SU-2026:24651-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.41.1.160000.2.32 | SUSE-SU-2026:24662-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.41.1.160000.2.32 | SUSE-SU-2026:24643-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.41.1 | SUSE-SU-2026:24648-1, SUSE-SU-2026:24643-1 |
| SLE Micro 6.1 | kernel-default-base | 6.4.0-159998.55.1.159998.21.41 | SUSE-SU-2026:24619-1 |
| SLE Micro 6.1 | kernel-source +2 | 6.4.0-159998.55.1 | SUSE-SU-2026:24619-1 |
| SLE Micro 6.0 | kernel-default-base | 6.4.0-159998.55.1.159998.21.42 | SUSE-SU-2026:24550-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-159998.55.1 | SUSE-SU-2026:24550-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.90.1 | SUSE-SU-2026:5091-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_24 | 1-150700.15.3.1 | SUSE-SU-2026:5091-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.1 | kernel-default-base | 6.12.0-160100.9.1.160100.3.14 | openSUSE-SU-2026:22309-1 |
| openSUSE Leap 16.1 | kernel-nvidia64kb +2 | 6.12.0-160100.7.1 | openSUSE-SU-2026:22307-1 |
| openSUSE Leap 16.1 | kernel-rt +11 | 6.12.0-160100.9.1 | openSUSE-SU-2026:22309-1 |
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.41.1.160000.2.31 | openSUSE-SU-2026:22266-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.41.1 | openSUSE-SU-2026:22266-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.18.56-125.164 +1 | 1:1.0-0.amzn2023 | ALAS2023-2026-3335, ALAS2023-2026-3251 |
| Amazon Linux 2023 | perf6.12 +11 | 1:6.12.113-138.209.amzn2023 | ALAS2023-2026-3335 |
| Amazon Linux 2023 | perf6.18 +12 | 1:6.18.56-125.164.amzn2023 | ALAS2023-2026-3251 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | No fix yet | — |
Advisories 27
- openSUSE-SU-2026:22309-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 14, 2026
- openSUSE-SU-2026:22307-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 14, 2026
- openSUSE-SU-2026:22266-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 14, 2026
- USN-9091-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9020-1 linux-aws-7.0, linux-azure-fde, linux-azure-fde-7.0, linux-gcp-7.0, linux-gke, linux-oracle-7.0, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9022-1 linux, linux-aws, linux-azure, linux-azure-fips, linux-gcp, linux-gke, linux-ibm, linux-lowlatency, linux-oracle, linux-vmware vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9025-1 linux-oracle-6.8, linux-raspi, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9024-1 linux-aws-6.8, linux-gcp-6.8, linux-ibm-6.8, linux-lowlatency-hwe-6.8, linux-nvidia, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9023-1 linux-aws-fips, linux-gcp-fips, linux-gkeop, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9026-1 linux-azure-6.8, linux-azure-fde-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9021-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9039-1 linux-azure-fde vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9040-1 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9066-1 linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9019-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 13, 2026
- USN-9018-2 linux-hwe-7.0 vulnerabilities Ubuntu Security Notices (USN) · Nov 12, 2026
- WID-SEC-2026-4019 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- SUSE-SU-2026:24662-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 12, 2026
- SUSE-SU-2026:24651-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 12, 2026
- SUSE-SU-2026:24643-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 12, 2026
- SUSE-SU-2026:24648-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 12, 2026
- SUSE-SU-2026:24619-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 12, 2026
- USN-9018-1 linux, linux-aws, linux-gcp, linux-ibm, linux-oem-7.0, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 11, 2026
- SUSE-SU-2026:24550-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 6, 2026
- SUSE-SU-2026:5091-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Nov 4, 2026
- ALAS2023-2026-3335 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Nov 2, 2026
- ALAS2023-2026-3251 Important: kernel6.18 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 26, 2026
References
- https://git.kernel.org/stable/c/d97da42e9de577dc827d4e8866e6971deefe2d9c
- https://git.kernel.org/stable/c/d86775e79838d7d2e38ccf506a7d0f8e2dd4d5d0
- https://git.kernel.org/stable/c/9742905d9ed5bf23ebe4c100dec80b6bc50fb522
- https://git.kernel.org/stable/c/a0ed07b5bbb2d8fcef86810453216070691816e7
- https://git.kernel.org/stable/c/420ca35af891d33522cc08504768ccd60a4c450a
- https://git.kernel.org/stable/c/dc614d6bc991740d41d5a99ac7765c4b675dda88