In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
KVM: x86\/mmu: WARN and clear role.invalid when creating a child shadow page<\/p>\n
Explicitly clear role.invalid when deriving a child shadow page’s role from
\nits parent to harden against bugs elsewhere in KVM, as violating KVM’s
\ninvariant that invalid pages are NOT on the list of active MMU pages leads
\nto use-after-free due to __kvm_mmu_prepare_zap_page() using list_add()
\ninstead of list_move() when processing an invalid shadow page, i.e. makes a
\nbad situation far worse.<\/p>\n
Yell loudly if the parent is invalid, as it means KVM has missed a validity
\ncheck, i.e. KVM is attempting to map memory using an invalid\/obsolete root,
\nbut continue on as the child is otherwise still a valid shadow page.<\/p>\n
==================================================================
\n BUG: KASAN: slab-use-after-free in __kvm_mmu_get_shadow_page+0x1817\/0x1860 [kvm]
\n Write of size 8 at addr ff11000153dd1368 by task repro\/853<\/p>\n
CPU: 1 UID: 1000 PID: 853 Comm: repro Not tainted 7.2.0-rc2-3aec122bdcaf-next-vm #5 PREEMPT
\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02\/06\/2015
\n Call Trace:<\/p>\n
dump_stack_lvl+0x4b\/0x70
\n print_report+0x153\/0x49c
\n kasan_report+0xbc\/0xf0
\n __kvm_mmu_get_shadow_page+0x1817\/0x1860 [kvm]
\n mmu_alloc_root+0x141\/0x320 [kvm]
\n kvm_mmu_load+0x612\/0x20f0 [kvm]
\n kvm_arch_vcpu_ioctl_run+0x3dd5\/0x6150 [kvm]
\n kvm_vcpu_ioctl+0x5e4\/0x10d0 [kvm]
\n __x64_sys_ioctl+0x131\/0x1b0
\n do_syscall_64+0x67\/0x5f0
\n entry_SYSCALL_64_after_hwframe+0x4b\/0x53<\/p>\n
Allocated by task 853:
\n kasan_save_stack+0x20\/0x40
\n kasan_save_track+0x14\/0x30
\n __kasan_slab_alloc+0x5f\/0x70
\n kmem_cache_alloc_noprof+0xfe\/0x2e0
\n __kvm_mmu_topup_memory_cache+0x135\/0x530 [kvm]
\n paging64_page_fault+0x318\/0x1e30 [kvm]
\n kvm_mmu_do_page_fault+0x21d\/0x630 [kvm]
\n kvm_mmu_page_fault+0x18c\/0x17b0 [kvm]
\n kvm_arch_vcpu_ioctl_run+0x1f35\/0x6150 [kvm]
\n kvm_vcpu_ioctl+0x5e4\/0x10d0 [kvm]
\n __x64_sys_ioctl+0x131\/0x1b0
\n do_syscall_64+0x67\/0x5f0
\n entry_SYSCALL_64_after_hwframe+0x4b\/0x53<\/p>\n
Freed by task 853:
\n kasan_save_stack+0x20\/0x40
\n kasan_save_track+0x14\/0x30
\n kasan_save_free_info+0x3b\/0x60
\n __kasan_slab_free+0x43\/0x70
\n kmem_cache_free+0xe2\/0x400
\n kvm_mmu_commit_zap_page.part.0+0x1e2\/0x310 [kvm]
\n kvm_mmu_free_roots+0x283\/0x560 [kvm]
\n kvm_arch_vcpu_ioctl_run+0x33c8\/0x6150 [kvm]
\n kvm_vcpu_ioctl+0x5e4\/0x10d0 [kvm]
\n __x64_sys_ioctl+0x131\/0x1b0
\n do_syscall_64+0x67\/0x5f0
\n entry_SYSCALL_64_after_hwframe+0x4b\/0x53<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
KVM: x86\/mmu: WARN and clear role.invalid when creating a child shadow page<\/p>\n
Explicitly clear role.invalid when deriving a child sh<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-3378","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/3378","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3378"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3378"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3378"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}