{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98395", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.346Z", "datePublished": "2026-10-14T13:25:57.887Z", "dateUpdated": "2026-10-14T13:25:57.887Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-14T13:25:57.887Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/entry: Fix irq_soft_mask corruption on replayed interrupt exit\n\nWhen __replay_soft_interrupts() replays a pending interrupt (e.g.\nPACA_IRQ_DEC -> timer_interrupt), it calls the handler directly with a\nsynthetic pt_regs. The DEFINE_INTERRUPT_HANDLER_ASYNC wrapper around\neach handler calls arch_interrupt_async_exit_prepare() on the way out,\nwhich calls arch_interrupt_exit_prepare() -> local_irq_disable() ->\narch_local_irq_disable(), which does:\n\n irq_soft_mask_set(IRQS_DISABLED) /* 0x1 */\n\nThis unconditionally overwrites irq_soft_mask with IRQS_DISABLED (0x1),\nstripping the IRQS_PMI_DISABLED (0x2) bit. The result is that\nirq_soft_mask is 0x1 instead of IRQS_ALL_DISABLED (0x3) when the\nhandler returns to __replay_soft_interrupts().\n\nFor a normally-taken interrupt this is harmless: the next interrupt\nalways enters through arch_interrupt_enter_prepare() which\nunconditionally sets irq_soft_mask to IRQS_ALL_DISABLED. But during\nreplay, next_interrupt() is called directly between replayed handlers\nwithout going back through arch_interrupt_enter_prepare(), so the\nstripped bit is never restored. next_interrupt() then fires a WARNING:\n\n WARNING: arch/powerpc/kernel/irq_64.c:75\n WARN_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED)\n\nThe warning was observed early in boot on a POWER10 pseries guest\nduring kmem_cache_init_late(), where a spinlock release triggers\ninterrupt replay that processes a pending timer interrupt.\n\nDebugger state confirming the bug:\n Before timer_interrupt(®s):\n irq_soft_mask = 0x3 (IRQS_ALL_DISABLED) correct\n irq_happened = 0x41 (HARD_DIS|REPLAYING) correct\n After timer_interrupt(®s) returns:\n irq_soft_mask = 0x1 (IRQS_DISABLED) WRONG - PMI bit stripped\n irq_happened = 0x41 unchanged\n\nThe fix is to replace local_irq_disable() with hard_irq_disable().\n\nhard_irq_disable() is the right primitive here for two reasons:\n\n1. On PPC64 (hw_irq.h:301) it calls irq_soft_mask_set_return(IRQS_ALL_DISABLED),\n setting the soft mask to 0x3 (both IRQS_DISABLED and IRQS_PMI_DISABLED),\n which preserves the PMI bit and fixes the WARNING. The additional\n work it does (__hard_irq_disable(), PACA_IRQ_HARD_DIS |=) is\n redundant but safe since both are already set at this point in the\n exit path; the trace_hardirqs_off() inside is guarded by\n if (!arch_irqs_disabled_flags(flags)) so it will not double-fire.\n\n2. On PPC32 (hw_irq.h:467) hard_irq_disable() maps to\n arch_local_irq_disable() -> __hard_irq_disable(), which clears\n MSR[EE] in hardware. This is exactly correct: PPC32 has no soft-mask\n PACA mechanism, so the hardware disable is the right way to satisfy\n irqentry_exit()'s requirement. This also fixes a build error on PPC32\n where irq_soft_mask_set() is only defined under CONFIG_PPC64:\n\n arch/powerpc/include/asm/entry-common.h:273: error: implicit\n declaration of function 'irq_soft_mask_set'\n\n Using hard_irq_disable() requires no #ifdef and is consistent with\n how the rest of the entry code (e.g. entry-common.h:463) handles the\n same PPC32/PPC64 split." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/include/asm/entry-common.h" ], "versions": [ { "version": "334f3f6d7a1660fd65597bad9960bfa33a716d35", "lessThan": "95cd316a896f1c1aa4ee4a817ba3d4691103c81b", "status": "affected", "versionType": "git" }, { "version": "334f3f6d7a1660fd65597bad9960bfa33a716d35", "lessThan": "63a7531ca31f9f097d9cc1cc3fe86ae683cdabdd", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/powerpc/include/asm/entry-common.h" ], "versions": [ { "version": "7.2", "status": "affected" }, { "version": "0", "lessThan": "7.2", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.7", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3-rc3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.2", "versionEndExcluding": "7.2.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.2", "versionEndExcluding": "7.3-rc3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/95cd316a896f1c1aa4ee4a817ba3d4691103c81b" }, { "url": "https://git.kernel.org/stable/c/63a7531ca31f9f097d9cc1cc3fe86ae683cdabdd" } ], "title": "powerpc/entry: Fix irq_soft_mask corruption on replayed interrupt exit", "x_generator": { "engine": "bippy-1.2.0" } } } }