{"id":"CVE-2026-93254","title":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64: entry: Avoid unnecessary local_irq_disable() on kernel exit\n\nCurrently, when exiting to kernel mode, we attempt involuntary\npreemption","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64: entry: Avoid unnecessary local_irq_disable() on kernel exit\n\nCurrently, when exiting to kernel mode, we attempt involuntary\npreemption. The preemption logic expe…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ae654112eac05f316ef31587fc55e4d7160d0086 < 49a61174186bed25d439ff37400c7ce5e3603e73","Linux >= ae654112eac05f316ef31587fc55e4d7160d0086 < 39aebe0e89469c2904e60b1e977e0d4dbf33326b","Linux 7.1"],"published":"2026-09-24","updated":"2026-09-24","sourceUpdated":"2026-09-24T16:17:21.807","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93254","references":[{"url":"https://git.kernel.org/stable/c/39aebe0e89469c2904e60b1e977e0d4dbf33326b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/49a61174186bed25d439ff37400c7ce5e3603e73","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-24T16:47:15.833Z","slug":"CVE-2026-93254","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\narm64: entry: Avoid unnecessary local_irq_disable() on kernel exit\n\nCurrently, when exiting to kernel mode, we attempt involuntary\npreemption. The preemption logic expects IRQs to be disabled, which is\nwhy we call local_irq_disable() before attempting preemption.\n\nHowever, depending on the context, local_irq_disable() may be\nunnecessary:\n\n- __el1_irq(), the non-NMI EL1 IRQ path, already has IRQs disabled, so\n  local_irq_disable() is redundant.\n\n- irqentry_exit_to_kernel_mode_preempt() immediately returns when\n  exiting from an NMI-like context, so calling local_irq_disable()\n  beforehand is unnecessary work.\n\nFurthermore, it confuses the pNMI state tracking when we are in a\ncontext with interrupts disabled and the GIC_PRIO_PSR_I_SET bit is set\nin the PMR, leading to a warning when\nCONFIG_ARM64_DEBUG_PRIORITY_MASKING=y:\n\n     WARNING: ./arch/arm64/include/asm/irqflags.h:63 at arm64_exit_to_kernel_mode+0xb8/0xc0, CPU#40: retsnoop/31805\n     CPU: 40 UID: 0 PID: 31805 Comm: retsnoop Not tainted 7.2.0-rc6-next-20260805 #7 PREEMPTLAZY\n     pstate: 234013c9 (nzCv DAIF +PAN -UAO +TCO +DIT +SSBS BTYPE=--)\n     pc : arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63)\n     lr : el1_abort (arch/arm64/kernel/entry-common.c:323)\n     pmr: 000000f0\n     Call trace:\n      arm64_exit_to_kernel_mode (arch/arm64/kernel/entry-common.c:63) (P)\n      el1_abort (arch/arm64/kernel/entry-common.c:323)\n      el1h_64_sync_handler (arch/arm64/kernel/entry-common.c:449)\n      el1h_64_sync (arch/arm64/kernel/entry.S:589)\n      [...]\n\nSplit arm64_exit_to_kernel_mode() into preempt, non-preempt, and\ndispatch parts so that we can avoid this extra work where it is not\nneeded and avoid breaking the pNMI tracking logic.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}