CVE-2025-40071 json
tty: n_gsm: Don't block input queue by waiting MSC
published 2025-10-28 12 mo ago modified 2026-10-30 9 d ago also EUVD-2025-36457
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 10%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
tty: n_gsm: Don't block input queue by waiting MSC
Currently gsm_queue() processes incoming frames and when opening a DLC channel it calls gsm_dlci_open() which calls gsm_modem_update(). If basic mode is used it calls gsm_modem_upd_via_msc() and it cannot block the input queue by waiting the response to come into the same input queue.
Instead allow sending Modem Status Command without waiting for remote end to respond. Define a new function gsm_modem_send_initial_msc() for this purpose. As MSC is only valid for basic encoding, it does not do anything for advanced or when convergence layer type 2 is used.
Patch / fix
- Linux Linux 5.16, 5.18, 6.1.191, 6.6.112, 6.12.53, 6.17.3, 6.18
- linux Debian 13 6.12.57-1
- linux Debian 14 6.17.6-1
debian advisories DEBIAN-CVE-2025-40071
- linux Ubuntu 24.04 LTS 6.8.0-106.106
- linux Ubuntu 25.10 6.17.0-14.14
- linux-aws Ubuntu 24.04 LTS 6.8.0-1050.53
- linux-aws Ubuntu 25.10 6.17.0-1007.7
- linux-gcp Ubuntu 24.04 LTS 6.8.0-1052.55
- linux-gcp Ubuntu 25.10 6.17.0-1007.7
- linux-gke Ubuntu 24.04 LTS 6.8.0-1048.53
- linux-ibm Ubuntu 24.04 LTS 6.8.0-1049.49
ubuntu advisories UBUNTU-CVE-2025-40071
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
- kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
- kernel-rt_debug Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
- kernel-source-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.58.1
- kernel-rt Linux Micro 6.2 6.12.0-160000.7.1
- kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.7.1
- kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.7.1
- kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.7.1
suse advisories SUSE-SU-2025:4301-1SUSE-SU-2025:21080-1SUSE-SU-2025:21147-1SUSE-SU-2025:21180-1SUSE-SU-2026:20561-1SUSE-SU-2025:21052-1
- kernel-source-longterm openSUSE Tumbleweed 6.18.16-1.1
- kernel-rt openSUSE Leap 16.0 6.12.0-160000.7.1
- dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.7.1
- kernel-64kb openSUSE Leap 16.0 6.12.0-160000.7.1
- kernel-syms openSUSE Leap 16.0 6.12.0-160000.7.1
- kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.7.1
- kernel-source openSUSE Leap 16.0 6.12.0-160000.7.1
- kernel-default openSUSE Leap 16.0 6.12.0-160000.7.1
opensuse advisories openSUSE-SU-2026:10301-1openSUSE-SU-2025:20091-1openSUSE-SU-2025:15702-1
- git.kernel.org/stable/c/8fcc22d6b90304d8b7436e101562218ea3faf73b commit
- git.kernel.org/stable/c/c36785f9de03df56ff9b8eca30fa681a12b2310d commit
- git.kernel.org/stable/c/5416e89b81b00443cb03c88df8da097ae091a141 commit
- git.kernel.org/stable/c/c5a2791a7f11939f05f95c01f0aec0c55bbf28d5 commit
- git.kernel.org/stable/c/3cf0b3c243e56bc43be560617416c1d9f301f44c commit
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2025-40071 updated cvss 6.1
kernel: tty: n_gsm: Don't block input queue by waiting MSC
-
Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 moreaffected: no fix available “Fix deferred”
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 10 kernelnot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
0.20% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/8fcc22d6b90304d8b7436e101562218ea3faf73b
- git.kernel.org /stable/c/c36785f9de03df56ff9b8eca30fa681a12b2310d
- git.kernel.org /stable/c/5416e89b81b00443cb03c88df8da097ae091a141
- git.kernel.org /stable/c/c5a2791a7f11939f05f95c01f0aec0c55bbf28d5
- git.kernel.org /stable/c/3cf0b3c243e56bc43be560617416c1d9f301f44c
Sources
- CVE List CVE-2025-40071
- NVD CVE-2025-40071
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