{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group()\n\nAl reported a possible use-after-free (UAF) in kvm_spapr_tce_attach_iommu_group().\n\nIt looks up `stt` from tablefd, but then continues to use it after doing\nfdput() on the returned fd. After the fdput() the tablefd is free to be\nclosed by another thread. The close calls kvm_spapr_tce_release() and\nthen release_spapr_tce_table() (via call_rcu()) which frees `stt`.\n\nAlthough there are calls to rcu_read_lock() in\nkvm_spapr_tce_attach_iommu_group() they are not sufficient to prevent\nthe UAF, because `stt` is used outside the locked regions.\n\nWith an artifcial delay after the fdput() and a userspace program which\ntriggers the race, KASAN detects the UAF:\n\n  BUG: KASAN: slab-use-after-free in kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]\n  Read of size 4 at addr c000200027552c30 by task kvm-vfio/2505\n  CPU: 54 PID: 2505 Comm: kvm-vfio Not tainted 6.10.0-rc3-next-20240612-dirty #1\n  Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV\n  Call Trace:\n    dump_stack_lvl+0xb4/0x108 (unreliable)\n    print_report+0x2b4/0x6ec\n    kasan_report+0x118/0x2b0\n    __asan_load4+0xb8/0xd0\n    kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]\n    kvm_vfio_set_attr+0x524/0xac0 [kvm]\n    kvm_device_ioctl+0x144/0x240 [kvm]\n    sys_ioctl+0x62c/0x1810\n    system_call_exception+0x190/0x440\n    system_call_vectored_common+0x15c/0x2ec\n  ...\n  Freed by task 0:\n   ...\n   kfree+0xec/0x3e0\n   release_spapr_tce_table+0xd4/0x11c [kvm]\n   rcu_core+0x568/0x16a0\n   handle_softirqs+0x23c/0x920\n   do_softirq_own_stack+0x6c/0x90\n   do_softirq_own_stack+0x58/0x90\n   __irq_exit_rcu+0x218/0x2d0\n   irq_exit+0x30/0x80\n   arch_local_irq_restore+0x128/0x230\n   arch_local_irq_enable+0x1c/0x30\n   cpuidle_enter_state+0x134/0x5cc\n   cpuidle_enter+0x6c/0xb0\n   call_cpuidle+0x7c/0x100\n   do_idle+0x394/0x410\n   cpu_startup_entry+0x60/0x70\n   start_secondary+0x3fc/0x410\n   start_secondary_prolog+0x10/0x14\n\nFix it by delaying the fdput() until `stt` is no longer in use, which\nis effectively the entire function. To keep the patch minimal add a call\nto fdput() at each of the existing return paths. Future work can convert\nthe function to goto or __cleanup style cleanup.\n\nWith the fix in place the test case no longer triggers the UAF."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "arch/powerpc/kvm/book3s_64_vio.c"
               ],
               "versions": [
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "be847bb20c80",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "4cdf6926f443",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "b26c8c85463e",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "5f856023971f",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "82c7a4cf14aa",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "9975f93c760a",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "a986fa57fd81",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "arch/powerpc/kvm/book3s_64_vio.c"
               ],
               "versions": [
                  {
                     "version": "5.4.281",
                     "lessThanOrEqual": "5.4.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.223",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.164",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1.101",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6.42",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.9.11",
                     "lessThanOrEqual": "6.9.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.10",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/be847bb20c809de8ac124431b556f244400b0491"
            },
            {
               "url": "https://git.kernel.org/stable/c/4cdf6926f443c84f680213c7aafbe6f91a5fcbc0"
            },
            {
               "url": "https://git.kernel.org/stable/c/b26c8c85463ef27a522d24fcd05651f0bb039e47"
            },
            {
               "url": "https://git.kernel.org/stable/c/5f856023971f97fff74cfaf21b48ec320147b50a"
            },
            {
               "url": "https://git.kernel.org/stable/c/82c7a4cf14aa866f8f7f09e662b02eddc49ee0bf"
            },
            {
               "url": "https://git.kernel.org/stable/c/9975f93c760a32453d7639cf6fcf3f73b4e71ffe"
            },
            {
               "url": "https://git.kernel.org/stable/c/a986fa57fd81a1430e00b3c6cf8a325d6f894a63"
            }
         ],
         "title": "KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group()",
         "x_generator": {
            "engine": "bippy-c9c4e1df01b2"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-41070",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}