CVE-2024-26709 powerpc/iommu: Fix the missing iommu_group_put() during platform domain attach
A missing reference count decrement in the Linux kernel's PowerPC IOMMU code causes a kernel bug and system crash during specific device removal operations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-26709?
CVE-2024-26709 is a medium-severity denial of service vulnerability in Linux kernel, published on 3 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
powerpc/iommu: Fix the missing iommu_group_put() during platform domain attach
The function spapr_tce_platform_iommu_attach_dev() is missing to call iommu_group_put() when the domain is already set. This refcount leak shows up with BUG_ON() during DLPAR remove operation as:
KernelBug: Kernel bug in state 'None': kernel BUG at arch/powerpc/platforms/pseries/iommu.c:100! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=8192 NUMA pSeries <snip> Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_016) hv:phyp pSeries NIP: c0000000000ff4d4 LR: c0000000000ff4cc CTR: 0000000000000000 REGS: c0000013aed5f840 TRAP: 0700 Tainted: G I (6.8.0-rc3-autotest-g99bd3cb0d12e) MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 44002402 XER: 20040000 CFAR: c000000000a0d170 IRQMASK: 0 ... NIP iommu_reconfig_notifier+0x94/0x200 LR iommu_reconfig_notifier+0x8c/0x200 Call Trace: iommu_reconfig_notifier+0x8c/0x200 (unreliable) notifier_call_chain+0xb8/0x19c blocking_notifier_call_chain+0x64/0x98 of_reconfig_notify+0x44/0xdc of_detach_node+0x78/0xb0 ofdt_write.part.0+0x86c/0xbb8 proc_reg_write+0xf4/0x150 vfs_write+0xf8/0x488 ksys_write+0x84/0x140 system_call_exception+0x138/0x330 system_call_vectored_common+0x15c/0x2ec
The patch adds the missing iommu_group_put() call.
Which versions are affected by CVE-2024-26709?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-26709?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-26709 being exploited?
There is no known exploitation of CVE-2024-26709 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-26709, DEBIAN-CVE-2024-26709, GHSA-mq9q-ghqw-348q, UBUNTU-CVE-2024-26709.