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CVE-2026-93260
powerpc/xive: propagate IPI init errors to prevent use-after-free
Published 2026-09-24 (24 days ago) by the Linux kernel CNA. Subsystem arch/powerpc. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-93260 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | vulnerable | 6.12.113-1 | No fix published anywhere yet, neither in Debian nor upstream for the series trixie tracks. Watch the Debian tracker page for this CVE. Advisories for trixie have historically landed a median of 11 days after publication. |
| Debian 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
When xive_init_ipis() fails (e.g. irq_domain_alloc_irqs() fails), the error path frees the global xive_ipis array. However, xive_smp_probe() previously ignored this failure and proceeded to call xive_setup_cpu_ipi(), which dereferences the already-freed xive_ipis pointer -- a use-after-free. Now that xive_smp_probe() returns int (previous patch), propagate the error from xive_init_ipis() and xive_setup_cpu_ipi() through xive_smp_probe(). Check the return value in both pnv_smp_probe() and pSeries_smp_probe() so that IPI setup is aborted cleanly on failure, avoiding the use-after-free.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
arch/powerpc/platforms/powernv/smp.c
arch/powerpc/platforms/pseries/smp.c
arch/powerpc/sysdev/xive/common.c
- What this is
- LINUX FOR POWERPC (32-BIT AND 64-BIT)MAINTAINERS section matched on arch/powerpc/ · linuxppc-dev@lists.ozlabs.org · Supported
Check it on the machine
grep -wE 'CONFIG_PPC_POWERNV|CONFIG_SMP' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormYnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/arm64, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, i386/686, i386/686-pae, i386/rt/686-pae
- trixieYnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, riscv64/riscv64, s390x/s390x
- forky, sidYnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, riscv64/riscv64, s390x/s390x
- Y
- built in where it is built at all; some flavours do not build it
- Build switches
- CONFIG_PPC_POWERNV, CONFIG_SMP
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-09-24 (24 days ago)source
- CVSS
- 7.4 high
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.14%, higher than 3.2% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- arch/powerpc
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.12 | 6.18.57 | 5c9ab0c9cede |
| 4.12 | 7.2.6 | c554a8d376d5 |
| 4.12 | 7.3 | 411a3c016e7a |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The UAF is in xive_setup_cpu_ipi() after xive_init_ipis() kfree's xive_ipis, reached only from kernel_init_freeable()->smp_prepare_cpus()->pnv_smp_probe()/pSeries_smp_probe()->xive_smp_probe(); no protocol message or received packet supplies the trigger.
- AC:HAttack complexity, high
- The free-then-use fires only when irq_domain_alloc_irqs() fails in xive_init_ipis()'s for_each_node loop (irq_desc ENOMEM/ENOSPC), after which kfree(xive_ipis) runs; that allocator failure during early SMP probe cannot be induced on demand.
- PR:NPrivileges required, none
- xive_smp_probe() runs as swapper/0 from smp_prepare_cpus() in kernel_init_freeable() before userspace, with no capable() or credential check on pnv_smp_probe() or pSeries_smp_probe().
- UI:NUser interaction, none
- SMP IPI probe is invoked unconditionally by smp_prepare_cpus() during ordinary boot once xive_core_init() has set __xive_enabled; no victim mount, file open, or other interactive step is required.
- S:UScope, unchanged
- The dangling xive_ipis dereference corrupts heap in the same Linux instance that runs XIVE (PowerNV host or pSeries guest); it is not a KVM/Xen guest-to-host escape or an IOMMU/DMA boundary bypass.
- C:HConfidentiality impact, high
- After kfree(xive_ipis) without NULLing, xive_ipi_cpu_to_irq() and xive_request_ipi() read xid->irq and xid->name from the freed xive_ipi_desc array; that heap use-after-free can disclose whatever reclaimed the slab.
- I:HIntegrity impact, high
- xive_request_ipi() then atomic_inc_return(&xid->started) on the freed descriptor and request_irq(xid->irq, xive_muxed_ipi_action) using the UAF-read virq, a write-after-free of the xive_ipi_desc slab that can corrupt a reused object and install a handler on the wrong irq.
- A:HAvailability impact, high
- Dereferencing the kfree'd xive_ipis pointer in xive_setup_cpu_ipi() during xive_smp_probe() oopses or panics the kernel while bringing up SMP, so the machine fails to boot.