{"id":"DEBIAN-CVE-2024-41070","details":"In the Linux kernel, the following vulnerability has been resolved:  KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group()  Al reported a possible use-after-free (UAF) in kvm_spapr_tce_attach_iommu_group().  It looks up `stt` from tablefd, but then continues to use it after doing fdput() on the returned fd. After the fdput() the tablefd is free to be closed by another thread. The close calls kvm_spapr_tce_release() and then release_spapr_tce_table() (via call_rcu()) which frees `stt`.  Although there are calls to rcu_read_lock() in kvm_spapr_tce_attach_iommu_group() they are not sufficient to prevent the UAF, because `stt` is used outside the locked regions.  With an artifcial delay after the fdput() and a userspace program which triggers the race, KASAN detects the UAF:    BUG: KASAN: slab-use-after-free in kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]   Read of size 4 at addr c000200027552c30 by task kvm-vfio/2505   CPU: 54 PID: 2505 Comm: kvm-vfio Not tainted 6.10.0-rc3-next-20240612-dirty #1   Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV   Call Trace:     dump_stack_lvl+0xb4/0x108 (unreliable)     print_report+0x2b4/0x6ec     kasan_report+0x118/0x2b0     __asan_load4+0xb8/0xd0     kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm]     kvm_vfio_set_attr+0x524/0xac0 [kvm]     kvm_device_ioctl+0x144/0x240 [kvm]     sys_ioctl+0x62c/0x1810     system_call_exception+0x190/0x440     system_call_vectored_common+0x15c/0x2ec   ...   Freed by task 0:    ...    kfree+0xec/0x3e0    release_spapr_tce_table+0xd4/0x11c [kvm]    rcu_core+0x568/0x16a0    handle_softirqs+0x23c/0x920    do_softirq_own_stack+0x6c/0x90    do_softirq_own_stack+0x58/0x90    __irq_exit_rcu+0x218/0x2d0    irq_exit+0x30/0x80    arch_local_irq_restore+0x128/0x230    arch_local_irq_enable+0x1c/0x30    cpuidle_enter_state+0x134/0x5cc    cpuidle_enter+0x6c/0xb0    call_cpuidle+0x7c/0x100    do_idle+0x394/0x410    cpu_startup_entry+0x60/0x70    start_secondary+0x3fc/0x410    start_secondary_prolog+0x10/0x14  Fix it by delaying the fdput() until `stt` is no longer in use, which is effectively the entire function. To keep the patch minimal add a call to fdput() at each of the existing return paths. Future work can convert the function to goto or __cleanup style cleanup.  With the fix in place the test case no longer triggers the UAF.","modified":"2026-09-15T09:03:14.362546179Z","published":"2024-07-29T15:15:14.787Z","upstream":["CVE-2024-41070"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2024-41070"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.1.106-1"}]}],"versions":["6.1.27-1","6.1.37-1","6.1.38-1","6.1.38-2","6.1.38-2~bpo11+1","6.1.38-3","6.1.38-4","6.1.38-4~bpo11+1","6.1.52-1","6.1.55-1","6.1.55-1~bpo11+1","6.1.64-1","6.1.66-1","6.1.67-1","6.1.69-1","6.1.69-1~bpo11+1","6.1.76-1","6.1.76-1~bpo11+1","6.1.82-1","6.1.85-1","6.1.90-1","6.1.90-1~bpo11+1","6.1.94-1","6.1.94-1~bpo11+1","6.1.98-1","6.1.99-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-41070.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.9.11-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-41070.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.9.11-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2024-41070.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}