CVE-2026-23433 Details
Description
In the Linux kernel, the following vulnerability has been resolved: arm_mpam: Fix null pointer dereference when restoring bandwidth counters When an MSC supporting memory bandwidth monitoring is brought offline and then online, mpam_restore_mbwu_state() calls __ris_msmon_read() via ipi to restore the configuration of the bandwidth counters. It doesn't care about the value read, mbwu_arg.val, and doesn't set it leading to a null pointer dereference when __ris_msmon_read() adds to it. This results in a kernel oops with a call trace such as: Call trace: __ris_msmon_read+0x19c/0x64c (P) mpam_restore_mbwu_state+0xa0/0xe8 smp_call_on_cpu_callback+0x1c/0x38 process_one_work+0x154/0x4b4 worker_thread+0x188/0x310 kthread+0x11c/0x130 ret_from_fork+0x10/0x20 Provide a local variable for val to avoid __ris_msmon_read() dereferencing a null pointer when adding to val.
A null pointer dereference vulnerability has been identified in the Linux kernel's memory bandwidth monitoring feature. When a Monitoring State Controller (MSC) that supports this feature is taken offline and then brought back online, the function 'mpam_restore_mbwu_state()' attempts to restore the bandwidth counter configuration. However, it fails to properly initialize a variable that holds the value read from the counter, leading to a dereference of a null pointer. This flaw causes a kernel oops, which can be observed in the call trace. The vulnerability has been addressed by modifying the code to ensure that the variable is correctly set before it is used, preventing the null pointer dereference.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been fixed. Instructions for downloading the patched version are available on the Linux Kernel Archive.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/4ad79c874e53ebb7fe3b8ae7ac6c858a2121f415 | kernel.org | Patch |
| https://git.kernel.org/stable/c/ac3e12bc195786d3d44d730b5b2259fd36191848 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-476 | NULL Pointer Dereference | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.19.1, < 6.19.10 6.19 - 7.0 rc1 7.0 rc2 7.0 rc3 7.0 rc4 7.0 rc5 7.0 rc6 7.0 rc7 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | kernel.org |
| Apr 23, 2026 | Initial Analysis | [email protected] |
| Apr 3, 2026 | New CVE Received | kernel.org |