CVE-2026-93259— powerpc/irq: Fix missing r2 clobber in PCREL inline assembly
Quick assessment
Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
在 Linux 内核中，已修复以下漏洞： powerpc/irq：修复 PCREL 内联汇编中 r2 寄存器未被列入破坏列表的问题 在启用 配置的模式下，r2 寄存器不再保留用于 TOC（表Of Contents）指针，而是作为调用者保存寄存器（caller-saved register）可用 [0]。 和 函数均使用内联汇编，在切换栈的过程中调用函数，但它们在破坏列表（clobber list）中均未声明 r2 寄存器。这导致编译器假设在这些调用前后 r2 的值保持不变，从而当被调用的函数（ 和 ）破坏 r2 寄
Possible ATT&CK Techniques 1 AI
T1690 · Prevent Command History LoggingAffected Version Matrix 12
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Linux | Linux | 7e3a68be42e10f5fa5890e97afc0afd992355bc3< dcc442a49c0f540193910dacdca7506bcadc7ec5 |
affected |
7e3a68be42e10f5fa5890e97afc0afd992355bc3< 602ee44415f3eaa7893f7fc488c7c1d4a0bdbd7a |
affected | ||
7e3a68be42e10f5fa5890e97afc0afd992355bc3< 90d953002cf0b233dd053a0e7cb67ab79cebd0e3 |
affected | ||
7e3a68be42e10f5fa5890e97afc0afd992355bc3< 7b0093b638c8f2b94b0778a69fd1ccad54299b29 |
affected | ||
7e3a68be42e10f5fa5890e97afc0afd992355bc3< 00be69070d91d2be978e752bb117a0a4db0e1281 |
affected | ||
6.4 |
affected | ||
< 6.4 |
unaffected | ||
6.6.157≤ 6.6.* |
unaffected | ||
| … +4 more rows | |||
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I. Basic Information for CVE-2026-93259
Vulnerability Information
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Vulnerability Title
powerpc/irq: Fix missing r2 clobber in PCREL inline assembly
Source: CVE Program / CVE List V5
Vulnerability Description
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
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Affected Products
II. Public POCs for CVE-2026-93259
| # | POC Description | Source Link | Shenlong Link |
|---|
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Patches & Fixes for CVE-2026-93259 (4)
Same Patch Batch · Linux · 2026-09-24 · 234 CVEs total
| CVE-2026-93207 | 9.8 CRITICAL | SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry |
| CVE-2026-97413 | 9.8 CRITICAL | RDMA/rtrs-srv: Fix integer underflow in process_read and process_write |
| CVE-2026-93228 | 9.1 CRITICAL | svcrdma: Reject Write/Reply chunks with segcount 0 |
| CVE-2026-93793 | 8.8 HIGH | wifi: iwlwifi: mvm: validate TX_CMD response layout |
| CVE-2026-93799 | 8.8 HIGH | wifi: iwlwifi: mvm: validate sta_id in BA window status notif |
| CVE-2026-93790 | 8.8 HIGH | wifi: iwlwifi: mvm: fix out-of-bounds tid_data access in BA notif |
| CVE-2026-93806 | 8.8 HIGH | wifi: cfg80211: validate assoc response length before status and IE access |
| CVE-2026-97442 | 8.8 HIGH | wifi: ath11k: fix invalid data access in ath11k_dp_rx_h_undecap_nwifi |
| CVE-2026-97509 | 8.8 HIGH | thunderbolt: Keep XDomain reference during the lifetime of a service |
| CVE-2026-97409 | 8.8 HIGH | nvme-fc: Do not cancel requests in io target before it is initialized |
| CVE-2026-93280 | 8.8 HIGH | greybus: audio: bound the topology section sizes against the fetched size |
| CVE-2026-93284 | 8.8 HIGH | drm/pagemap: dma-unmap pages before handling migration errors |
| CVE-2026-97451 | 8.4 HIGH | ACPICA: Fix integer overflow in acpi_ex_opcode_3A_1T_1R() (mid_op) |
| CVE-2026-97452 | 8.4 HIGH | ACPICA: Prevent adding invalid references |
| CVE-2026-97455 | 8.4 HIGH | ACPICA: Fix use-after-free in acpi_ds_terminate_control_method() |
| CVE-2026-97450 | 8.4 HIGH | ACPICA: validate handler object type in two places |
| CVE-2026-93827 | 8.4 HIGH | virtio-fs: avoid double-free on failed queue setup |
| CVE-2026-97433 | 8.2 HIGH | nvme: validate FDP configuration descriptor sizes |
| CVE-2026-93221 | 8.1 HIGH | nfsd: convert nfsd_net boolean flags to unsigned long flags word |
| CVE-2026-93786 | 8.1 HIGH | ksmbd: preserve VFS inherited POSIX ACL mask |
Showing top 20 of 234 CVEs. View all on vendor page → →
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V. Comments for CVE-2026-93259
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