In the Linux kernel, the following vulnerability has been resolved: powerpc/irq: Fix missing r2 clobber in PCREL inline assembly In CONFIG_PPC_KERNEL_PCREL mode, r2 is no longer reserved for the TOC pointer and is available as a caller-saved register [0]. Both call_do_irq() and call_do_softirq() use inline assembly to call functions with stack switching, but fail to list r2 in their clobber lists. This causes the compiler to assume r2 is preserved across these calls, leading to register corruption when the called functions (__do_irq and __do_softirq) clobber r2. As a result of this kernel crash during interrupt handling is seen and the kernel fails to boot: BUG: Unable to handle kernel data access on write at 0xc000000404697638 Faulting instruction address: 0xc0000000000181ec Oops: Kernel access of bad area, sig: 11 [#1] NIP [c0000000000181ec] __do_IRQ+0x6c/0xc0 With older GCC, the compiler would conservatively allocate callee-saved registers (like r31) for values spanning function calls, accidentally avoiding the bug: <__do_IRQ>: 00 00 00 60 nop a6 02 08 7c mflr r0 f8 ff e1 fb std r31,-8(r1) f0 ff c1 fb std r30,-16(r1) 2d 03 10 06 pla r31,53297316 ... 3d e8 ff 4b bl c0000000000165ac <__do_irq> 00 00 21 e8 ld r1,0(r1) 28 00 4d e9 ld r10,40(r13) 40 00 21 38 addi r1,r1,64 2a f9 aa 7f stdx r29,r10,r31 With newer GCC 14, the compiler uses r2 for such values, exposing the missing clobber specification: <__do_IRQ>: 00 00 00 60 nop a6 02 08 7c mflr r0 f0 ff c1 fb std r30,-16(r1) f8 ff e1 fb std r31,-8(r1) 29 02 10 06 pla r2,36252592 # c0000000022aadc0 <__irq_regs> ... 85 dc ff 4b bl c000000000015ee0 <__do_irq> 00 00 21 e8 ld r1,0(r1) 28 00 2d e9 ld r9,40(r13) 30 00 21 38 addi r1,r1,48 2a 11 c9 7f stdx r30,r9,r2 Fix this by adding r2 to the clobber list for both call_do_irq() and call_do_softirq() when CONFIG_PPC_KERNEL_PCREL is enabled. [0]: https://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg313226.html

An update of the linux package has been released.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - powerpc/irq: Fix missing r2 clobber in PCREL inline assembly In CONFIG_PPC_KERNEL_PCREL mode, r2 is no     longer reserved for the TOC pointer and is available as a caller-saved register [0]. Both call_do_irq()     and call_do_softirq() use inline assembly to call functions with stack switching, but fail to list r2 in     their clobber lists. This causes the compiler to assume r2 is preserved across these calls, leading to     register corruption when the called functions (__do_irq and __do_softirq) clobber r2. As a result of this     kernel crash during interrupt handling is seen and the kernel fails to boot: BUG: Unable to handle kernel     data access on write at 0xc000000404697638 Faulting instruction address: 0xc0000000000181ec Oops: Kernel     access of bad area, sig: 11 [#1] NIP [c0000000000181ec] __do_IRQ+0x6c/0xc0 With older GCC, the compiler     would conservatively allocate callee-saved registers (like r31) for values spanning function calls,     accidentally avoiding the bug: <__do_IRQ>: 00 00 00 60 nop a6 02 08 7c mflr r0 f8 ff e1 fb std r31,-8(r1)     f0 ff c1 fb std r30,-16(r1) 2d 03 10 06 pla r31,53297316 ... 3d e8 ff 4b bl c0000000000165ac <__do_irq> 00     00 21 e8 ld r1,0(r1) 28 00 4d e9 ld r10,40(r13) 40 00 21 38 addi r1,r1,64 2a f9 aa 7f stdx r29,r10,r31     With newer GCC 14, the compiler uses r2 for such values, exposing the missing clobber specification:
    <__do_IRQ>: 00 00 00 60 nop a6 02 08 7c mflr r0 f0 ff c1 fb std r30,-16(r1) f8 ff e1 fb std r31,-8(r1) 29     02 10 06 pla r2,36252592 # c0000000022aadc0 <__irq_regs> ... 85 dc ff 4b bl c000000000015ee0 <__do_irq> 00     00 21 e8 ld r1,0(r1) 28 00 2d e9 ld r9,40(r13) 30 00 21 38 addi r1,r1,48 2a 11 c9 7f stdx r30,r9,r2 Fix     this by adding r2 to the clobber list for both call_do_irq() and call_do_softirq() when     CONFIG_PPC_KERNEL_PCREL is enabled. [0]: https://www.mail-archive.com/gcc-     patches@gcc.gnu.org/msg313226.html (CVE-2026-93259)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
376443	Ubuntu 24.04 LTS / 26.04 LTS : Linux kernel vulnerabilities (USN-8959-1)	Nessus	Ubuntu Local Security Checks	Local	high
375113	Photon OS 5.0: Linux PHSA-2026-5.0-91-1014	Nessus	PhotonOS Local Security Checks	Local	high
375014	Photon OS 5.0: Linux PHSA-2026-5.0-92-1014	Nessus	PhotonOS Local Security Checks	Local	high
362907	Debian dla-4817 : ata-modules-6.12.107+deb12-armmp-di - security update	Nessus	Debian Local Security Checks	Local	high
351155	Debian dsa-6528 : ata-modules-6.12.111+deb13-armmp-di - security update	Nessus	Debian Local Security Checks	Local	high
349797	Linux Distros Unpatched Vulnerability : CVE-2026-93259	Nessus	Misc.	Local	medium

Detections

Analytics

CVE-2026-93259

high

Tenable Plugins

high

high

high

high

high

medium