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There are 15 CVE Records that match your search.
| Name | Description |
|---|---|
| CVE-2021-47094 | In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Don't advance iterator after restart due to yielding After dropping mmu_lock in the TDP MMU, restart the iterator during tdp_iter_next() and do not advance the iterator. Advancing the iterator results in skipping the top-level SPTE and all its children, which is fatal if any of the skipped SPTEs were not visited before yielding. When zapping all SPTEs, i.e. when min_level == root_level, restarting the iter and then invoking tdp_iter_next() is always fatal if the current gfn has as a valid SPTE, as advancing the iterator results in try_step_side() skipping the current gfn, which wasn't visited before yielding. Sprinkle WARNs on iter->yielded being true in various helpers that are often used in conjunction with yielding, and tag the helper with __must_check to reduce the probabily of improper usage. Failing to zap a top-level SPTE manifests in one of two ways. If a valid SPTE is skipped by both kvm_tdp_mmu_zap_all() and kvm_tdp_mmu_put_root(), the shadow page will be leaked and KVM will WARN accordingly. WARNING: CPU: 1 PID: 3509 at arch/x86/kvm/mmu/tdp_mmu.c:46 [kvm] RIP: 0010:kvm_mmu_uninit_tdp_mmu+0x3e/0x50 [kvm] Call Trace: <TASK> kvm_arch_destroy_vm+0x130/0x1b0 [kvm] kvm_destroy_vm+0x162/0x2a0 [kvm] kvm_vcpu_release+0x34/0x60 [kvm] __fput+0x82/0x240 task_work_run+0x5c/0x90 do_exit+0x364/0xa10 ? futex_unqueue+0x38/0x60 do_group_exit+0x33/0xa0 get_signal+0x155/0x850 arch_do_signal_or_restart+0xed/0x750 exit_to_user_mode_prepare+0xc5/0x120 syscall_exit_to_user_mode+0x1d/0x40 do_syscall_64+0x48/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae If kvm_tdp_mmu_zap_all() skips a gfn/SPTE but that SPTE is then zapped by kvm_tdp_mmu_put_root(), KVM triggers a use-after-free in the form of marking a struct page as dirty/accessed after it has been put back on the free list. This directly triggers a WARN due to encountering a page with page_count() == 0, but it can also lead to data corruption and additional errors in the kernel. WARNING: CPU: 7 PID: 1995658 at arch/x86/kvm/../../../virt/kvm/kvm_main.c:171 RIP: 0010:kvm_is_zone_device_pfn.part.0+0x9e/0xd0 [kvm] Call Trace: <TASK> kvm_set_pfn_dirty+0x120/0x1d0 [kvm] __handle_changed_spte+0x92e/0xca0 [kvm] __handle_changed_spte+0x63c/0xca0 [kvm] __handle_changed_spte+0x63c/0xca0 [kvm] __handle_changed_spte+0x63c/0xca0 [kvm] zap_gfn_range+0x549/0x620 [kvm] kvm_tdp_mmu_put_root+0x1b6/0x270 [kvm] mmu_free_root_page+0x219/0x2c0 [kvm] kvm_mmu_free_roots+0x1b4/0x4e0 [kvm] kvm_mmu_unload+0x1c/0xa0 [kvm] kvm_arch_destroy_vm+0x1f2/0x5c0 [kvm] kvm_put_kvm+0x3b1/0x8b0 [kvm] kvm_vcpu_release+0x4e/0x70 [kvm] __fput+0x1f7/0x8c0 task_work_run+0xf8/0x1a0 do_exit+0x97b/0x2230 do_group_exit+0xda/0x2a0 get_signal+0x3be/0x1e50 arch_do_signal_or_restart+0x244/0x17f0 exit_to_user_mode_prepare+0xcb/0x120 syscall_exit_to_user_mode+0x1d/0x40 do_syscall_64+0x4d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Note, the underlying bug existed even before commit 1af4a96025b3 ("KVM: x86/mmu: Yield in TDU MMU iter even if no SPTES changed") moved calls to tdp_mmu_iter_cond_resched() to the beginning of loops, as KVM could still incorrectly advance past a top-level entry when yielding on a lower-level entry. But with respect to leaking shadow pages, the bug was introduced by yielding before processing the current gfn. Alternatively, tdp_mmu_iter_cond_resched() could simply fall through, or callers could jump to their "retry" label. The downside of that approach is that tdp_mmu_iter_cond_resched() _must_ be called before anything else in the loop, and there's no easy way to enfornce that requirement. Ideally, KVM would handling the cond_resched() fully within the iterator macro (the code is actually quite clean) and avoid this entire class of bugs, but that is extremely difficult do wh ---truncated--- |
| CVE-2020-14381 | A flaw was found in the Linux kernel’s futex implementation. This flaw allows a local attacker to corrupt system memory or escalate their privileges when creating a futex on a filesystem that is about to be unmounted. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. |
| CVE-2018-9422 | In get_futex_key of futex.c, there is a use-after-free due to improper locking. This could lead to local escalation of privilege with no additional privileges needed. User interaction is not needed for exploitation. Product: Android Versions: Android kernel Android ID: A-74250718 References: Upstream kernel. |
| CVE-2018-6927 | The futex_requeue function in kernel/futex.c in the Linux kernel before 4.14.15 might allow attackers to cause a denial of service (integer overflow) or possibly have unspecified other impact by triggering a negative wake or requeue value. |
| CVE-2018-12896 | An issue was discovered in the Linux kernel through 4.17.3. An Integer Overflow in kernel/time/posix-timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically makes the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. For example, a local user can cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls. |
| CVE-2016-1880 | The Linux compatibility layer in the kernel in FreeBSD 9.3, 10.1, and 10.2 allows local users to read portions of kernel memory and potentially gain privilege via unspecified vectors, related to "handling of Linux futex robust lists." |
| CVE-2014-3153 | The futex_requeue function in kernel/futex.c in the Linux kernel through 3.14.5 does not ensure that calls have two different futex addresses, which allows local users to gain privileges via a crafted FUTEX_REQUEUE command that facilitates unsafe waiter modification. |
| CVE-2014-0205 | The futex_wait function in kernel/futex.c in the Linux kernel before 2.6.37 does not properly maintain a certain reference count during requeue operations, which allows local users to cause a denial of service (use-after-free and system crash) or possibly gain privileges via a crafted application that triggers a zero count. |
| CVE-2012-6647 | The futex_wait_requeue_pi function in kernel/futex.c in the Linux kernel before 3.5.1 does not ensure that calls have two different futex addresses, which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via a crafted FUTEX_WAIT_REQUEUE_PI command. |
| CVE-2012-0028 | The robust futex implementation in the Linux kernel before 2.6.28 does not properly handle processes that make exec system calls, which allows local users to cause a denial of service or possibly gain privileges by writing to a memory location in a child process. |
| CVE-2010-3086 | include/asm-x86/futex.h in the Linux kernel before 2.6.25 does not properly implement exception fixup, which allows local users to cause a denial of service (panic) via an invalid application that triggers a page fault. |
| CVE-2010-0623 | The futex_lock_pi function in kernel/futex.c in the Linux kernel before 2.6.33-rc7 does not properly manage a certain reference count, which allows local users to cause a denial of service (OOPS) via vectors involving an unmount of an ext3 filesystem. |
| CVE-2010-0622 | The wake_futex_pi function in kernel/futex.c in the Linux kernel before 2.6.33-rc7 does not properly handle certain unlock operations for a Priority Inheritance (PI) futex, which allows local users to cause a denial of service (OOPS) and possibly have unspecified other impact via vectors involving modification of the futex value from user space. |
| CVE-2006-3634 | The (1) __futex_atomic_op and (2) futex_atomic_cmpxchg_inatomic functions in Linux kernel 2.6.17-rc4 to 2.6.18-rc2 perform the atomic futex operation in the kernel address space instead of the user address space, which allows local users to cause a denial of service (crash). |
| CVE-2005-0937 | Some futex functions in futex.c for Linux kernel 2.6.x perform get_user calls while holding the mmap_sem semaphore, which could allow local users to cause a deadlock condition in do_page_fault by triggering get_user faults while another thread is executing mmap or other functions. |
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