CVE-2024-26709

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> powerpc/iommu: Fix the missing iommu_group_put() during platform domain attach<br /> <br /> The function spapr_tce_platform_iommu_attach_dev() is missing to call<br /> iommu_group_put() when the domain is already set. This refcount leak<br /> shows up with BUG_ON() during DLPAR remove operation as:<br /> <br /> KernelBug: Kernel bug in state &amp;#39;None&amp;#39;: kernel BUG at arch/powerpc/platforms/pseries/iommu.c:100!<br /> Oops: Exception in kernel mode, sig: 5 [#1]<br /> LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=8192 NUMA pSeries<br /> <br /> Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_016) hv:phyp pSeries<br /> NIP: c0000000000ff4d4 LR: c0000000000ff4cc CTR: 0000000000000000<br /> REGS: c0000013aed5f840 TRAP: 0700 Tainted: G I (6.8.0-rc3-autotest-g99bd3cb0d12e)<br /> MSR: 8000000000029033 CR: 44002402 XER: 20040000<br /> CFAR: c000000000a0d170 IRQMASK: 0<br /> ...<br /> NIP iommu_reconfig_notifier+0x94/0x200<br /> LR iommu_reconfig_notifier+0x8c/0x200<br /> Call Trace:<br /> iommu_reconfig_notifier+0x8c/0x200 (unreliable)<br /> notifier_call_chain+0xb8/0x19c<br /> blocking_notifier_call_chain+0x64/0x98<br /> of_reconfig_notify+0x44/0xdc<br /> of_detach_node+0x78/0xb0<br /> ofdt_write.part.0+0x86c/0xbb8<br /> proc_reg_write+0xf4/0x150<br /> vfs_write+0xf8/0x488<br /> ksys_write+0x84/0x140<br /> system_call_exception+0x138/0x330<br /> system_call_vectored_common+0x15c/0x2ec<br /> <br /> The patch adds the missing iommu_group_put() call.