Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved:can: bcm: defer rx_op deallocation to workqueue to fix thrtimer UAF
Commit f1b4e32aca08 ("can: bcm: use call_rcu() instead of costly
synchronize_rcu()") replaced synchronize_rcu() in bcm_delete_rx_op()
with call_rcu() and introduced the RX_NO_AUTOTIMER flag.
However, this flag check was omitted for thrtimer in the packet rx
fast-path. During BCM RX operation teardown, a concurrent RCU reader
(bcm_rx_handler) can race and re-arm thrtimer via
bcm_rx_update_and_send() after call_rcu() has been scheduled. Once
the RCU grace period elapses, bcm_op is freed. The subsequently
firing thrtimer then dereferences the deallocated op, causing a UAF.
Adding flag checks to the rx fast-path (bcm_rx_update_and_send) does not
fully close the TOCTOU race and introduces latency for every CAN frame.
Conversely, calling hrtimer_cancel() directly inside the RCU callback
(softirq context) is fatal as hrtimer_cancel() can sleep, triggering
a "scheduling while atomic" panic.
Resolve this by deferring the timer cancellation and memory free to a
dedicated unbound workqueue (bcm_wq). The RCU callback now queues a
work item to bcm_wq, which safely cancels both timers and deallocates
memory in sleepable process context. A dedicated workqueue is used to
prevent system-wide WQ saturation and is cleanly flushed/destroyed
on module unload to avoid rmmod page faults.
Since the deferred work can now outlive the calling context by an
unbounded amount, also take a reference on op->sk when it is assigned
and drop it only once the deferred work has cancelled both timers, so a
socket can no longer be freed out from under a still-armed timer whose
callback (bcm_send_to_user()) dereferences op->sk.
SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having important severity.
| CVSS detail | CNA (NVD) | Linux Kernel CNA | SUSE |
|---|---|---|---|
| Base Score | 7.8 | 7.8 | 7 |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | High |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality Impact | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
| CVSSv3 Version | 3.1 | 3.1 | 3.1 |
| CVSS detail | SUSE |
|---|---|
| Base Score | 7.3 |
| Vector | CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| Attack Vector | Local |
| Attack Complexity | Low |
| Attack Requirements | Present |
| Privileges Required | Low |
| User Interaction | None |
| Vulnerable System Confidentiality Impact | High |
| Vulnerable System Integrity Impact | High |
| Vulnerable System Availability Impact | High |
| Subsequent System Confidentiality Impact | None |
| Subsequent System Integrity Impact | None |
| Subsequent System Availability Impact | None |
| CVSSv4 Version | 4.0 |
Note from the SUSE Security Team on the kernel-default package
SUSE will no longer fix all CVEs in the Linux Kernel anymore, but declare some bug classes as won't fix. Please refer to TID 21496 for more details. SUSE Bugzilla entries: 1277523 [NEW], 1277865 [NEW] No SUSE Security Announcements cross referenced.Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| SUSE Linux Enterprise Desktop 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Desktop 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Availability Extension 16.0 | kernel-default | Already fixed |
| SUSE Linux Enterprise High Availability Extension 16.0 | kernel-source | Already fixed |
| SUSE Linux Enterprise High Availability Extension 16.1 | kernel-default | Already fixed |
| SUSE Linux Enterprise High Availability Extension 16.1 | kernel-source | Already fixed |
| SUSE Linux Enterprise Live Patching 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Live Patching 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Micro 5.3 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-rt | Affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-source | In progress |
| SUSE Linux Enterprise Micro 5.3 | kernel-source-rt | In progress |
| SUSE Linux Enterprise Micro 5.4 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-rt | Affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-source | In progress |
| SUSE Linux Enterprise Micro 5.4 | kernel-source-rt | In progress |
| SUSE Linux Enterprise Micro 5.5 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-source | In progress |
| SUSE Linux Enterprise Micro 5.5 | kernel-source-rt | In progress |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Real Time 15 SP7 | kernel-source-rt | Already fixed |
| SUSE Linux Enterprise Server 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 16.0 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 16.0 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server 16.1 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server 16.1 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP applications 16.0 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP applications 16.0 | kernel-source | Already fixed |
| SUSE Linux Enterprise Server for SAP applications 16.1 | kernel-default | Already fixed |
| SUSE Linux Enterprise Server for SAP applications 16.1 | kernel-source | Already fixed |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | kernel-default | Already fixed |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | kernel-source | Already fixed |
| SUSE Linux Micro 6.0 | kernel-default | Already fixed |
| SUSE Linux Micro 6.0 | kernel-source | Already fixed |
| SUSE Linux Micro 6.0 | kernel-source-rt | Already fixed |
| SUSE Linux Micro 6.1 | kernel-default | Already fixed |
| SUSE Linux Micro 6.1 | kernel-source | Already fixed |
| SUSE Linux Micro 6.1 | kernel-source-rt | Already fixed |
| SUSE Linux Micro 6.2 | kernel-default | Already fixed |
| SUSE Linux Micro 6.2 | kernel-source | Already fixed |
| SUSE Linux Micro Extras 6.0 | kernel-default | Already fixed |
| SUSE Linux Micro Extras 6.0 | kernel-source | Already fixed |
| SUSE Linux Micro Extras 6.0 | kernel-source-rt | Already fixed |
| SUSE Linux Micro Extras 6.1 | kernel-default | Already fixed |
| SUSE Linux Micro Extras 6.1 | kernel-source | Already fixed |
| SUSE Real Time Module 15 SP7 | kernel-source-rt | Already fixed |
| openSUSE Leap 16.0 | kernel-source | Already fixed |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-default | Not affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-default | Not affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-source | Affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE CaaS Platform 4.0 | kernel-source | Not affected |
| SUSE Enterprise Storage 6 | kernel-source | Not affected |
| SUSE Enterprise Storage 7 | kernel-source | Not affected |
| SUSE Enterprise Storage 7.1 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise Micro 5.0 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.1 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Real Time 15 SP5 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Server 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 11 SP4-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-source | Not affected |
| SUSE Manager Proxy 4.0 | kernel-source | Not affected |
| SUSE Manager Proxy 4.1 | kernel-source | Not affected |
| SUSE Manager Proxy 4.2 | kernel-source | Not affected |
| SUSE Manager Proxy 4.3 | kernel-source | Affected |
| SUSE Manager Proxy LTS 4.3 | kernel-source | Affected |
| SUSE Manager Retail Branch Server 4.0 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.1 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.2 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.3 | kernel-source | Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | kernel-source | Affected |
| SUSE Manager Server 4.0 | kernel-source | Not affected |
| SUSE Manager Server 4.1 | kernel-source | Not affected |
| SUSE Manager Server 4.2 | kernel-source | Not affected |
| SUSE Manager Server 4.3 | kernel-source | Affected |
| SUSE Manager Server LTS 4.3 | kernel-source | Affected |
| SUSE Real Time Module 15 SP4 | kernel-source-rt | Affected |
| SUSE Real Time Module 15 SP5 | kernel-source-rt | Affected |
| openSUSE Leap 15.3 | kernel-source | Not affected |
| openSUSE Leap 15.4 | kernel-source | Affected |
| openSUSE Leap 15.4 | kernel-source-rt | Affected |
| openSUSE Leap 15.5 | kernel-source | Affected |
| openSUSE Leap 15.5 | kernel-source-rt | Affected |
| openSUSE Leap 15.6 | kernel-source | Affected |
SUSE Timeline for this CVE
CVE page created: Mon Aug 31 13:50:34 2026CVE page last modified: Thu Sep 3 19:59:00 2026