CVE-2026-93254
arm64: entry: Avoid unnecessary local_irq_disable() on kernel exit
Description
In the Linux kernel, the following vulnerability has been resolved: arm64: entry: Avoid unnecessary local_irq_disable() on kernel exit Currently, when exiting to kernel mode, we attempt involuntary preemption. The preemption logic expects IRQs to be disabled, which is why we call local_irq_disable() before attempting preemption. However, depending on the context, local_irq_disable() may be unnecessary: - __el1_irq(), the non-NMI EL1 IRQ path, already has IRQs disabled, so local_irq_disable() is redundant. - irqentry_exit_to_kernel_mode_preempt() immediately returns when exiting from an NMI-like context, so calling local_irq_disable() beforehand is unnecessary work. Furthermore, it confuses the pNMI state tracking when we are in a context with interrupts disabled and the GIC_PRIO_PSR_I_SET bit is set in the PMR, leading to a warning when CONFIG_ARM64_DEBUG_PRIORITY_MASKING=y: WARNING: ./arch/arm64/include/asm/irqflags.h:63 at arm64_exit_to_kernel_mode+0xb8/0xc0, CPU#40: retsnoop/31805 CPU: 40 UID: 0 PID: 31805 Comm: retsnoop Not tainted 7.2.0-rc6-next-20260805 #7 PREEMPTLAZY pstate: 234013c9 (nzCv DAIF +PAN -UAO +TCO +DIT +SSBS BTYPE=--) pc : arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63) lr : el1_abort (arch/arm64/kernel/entry-common.c:323) pmr: 000000f0 Call trace: arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63) (P) el1_abort (arch/arm64/kernel/entry-common.c:323) el1h_64_sync_handler (arch/arm64/kernel/entry-common.c:449) el1h_64_sync (arch/arm64/kernel/entry.S:589) [...] Split arm64_exit_to_kernel_mode() into preempt, non-preempt, and dispatch parts so that we can avoid this extra work where it is not needed and avoid breaking the pNMI tracking logic.
INFO
Published Date :
Sept. 24, 2026, 4:17 p.m.
Last Modified :
Sept. 24, 2026, 4:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the latest stable version.
- Apply patches that address entry point preemption logic.
- Ensure correct interrupt and priority masking configurations.
- Test the updated kernel for stability and security.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-93254.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/39aebe0e89469c2904e60b1e977e0d4dbf33326b | |
| https://git.kernel.org/stable/c/49a61174186bed25d439ff37400c7ce5e3603e73 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-93254 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-93254
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-93254 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-93254 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 24, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: arm64: entry: Avoid unnecessary local_irq_disable() on kernel exit Currently, when exiting to kernel mode, we attempt involuntary preemption. The preemption logic expects IRQs to be disabled, which is why we call local_irq_disable() before attempting preemption. However, depending on the context, local_irq_disable() may be unnecessary: - __el1_irq(), the non-NMI EL1 IRQ path, already has IRQs disabled, so local_irq_disable() is redundant. - irqentry_exit_to_kernel_mode_preempt() immediately returns when exiting from an NMI-like context, so calling local_irq_disable() beforehand is unnecessary work. Furthermore, it confuses the pNMI state tracking when we are in a context with interrupts disabled and the GIC_PRIO_PSR_I_SET bit is set in the PMR, leading to a warning when CONFIG_ARM64_DEBUG_PRIORITY_MASKING=y: WARNING: ./arch/arm64/include/asm/irqflags.h:63 at arm64_exit_to_kernel_mode+0xb8/0xc0, CPU#40: retsnoop/31805 CPU: 40 UID: 0 PID: 31805 Comm: retsnoop Not tainted 7.2.0-rc6-next-20260805 #7 PREEMPTLAZY pstate: 234013c9 (nzCv DAIF +PAN -UAO +TCO +DIT +SSBS BTYPE=--) pc : arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63) lr : el1_abort (arch/arm64/kernel/entry-common.c:323) pmr: 000000f0 Call trace: arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63) (P) el1_abort (arch/arm64/kernel/entry-common.c:323) el1h_64_sync_handler (arch/arm64/kernel/entry-common.c:449) el1h_64_sync (arch/arm64/kernel/entry.S:589) [...] Split arm64_exit_to_kernel_mode() into preempt, non-preempt, and dispatch parts so that we can avoid this extra work where it is not needed and avoid breaking the pNMI tracking logic. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/93xxx/CVE-2026-93254.json">CVE-2026-93254</a> Added Reference https://git.kernel.org/stable/c/39aebe0e89469c2904e60b1e977e0d4dbf33326b Added Reference https://git.kernel.org/stable/c/49a61174186bed25d439ff37400c7ce5e3603e73