CVE-2021-29657

arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.

arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.

This kernel-linus update is based on upstream 5.10.30 and fixes at least the following security issues:

nfc: fix refcount leak in llcp_sock_bind() (CVE-2020-25670)

nfc: fix refcount leak in llcp_sock_connect() (CVE-2020-25671)

nfc: fix memory leak in llcp_sock_connect() (CVE-2020-25672)

firewire: nosy: Fix a use-after-free bug in nosy_ioctl() (CVE-2021-3483)

BPF JIT compilers in the Linux kernel through 5.11.12 have incorrect computation of branch displacements, allowing them to execute arbitrary code within the kernel context (CVE-2021-29154).

KVM: SVM: load control fields from VMCB12 before checking them (CVE-2021-29657).

For other upstream fixes, see the referenced changelogs.

This kernel update is based on upstream 5.10.30 and fixes at least the following security issues:

nfc: fix refcount leak in llcp_sock_bind() (CVE-2020-25670)

nfc: fix refcount leak in llcp_sock_connect() (CVE-2020-25671)

nfc: fix memory leak in llcp_sock_connect() (CVE-2020-25672)

firewire: nosy: Fix a use-after-free bug in nosy_ioctl() (CVE-2021-3483)

BPF JIT compilers in the Linux kernel through 5.11.12 have incorrect computation of branch displacements, allowing them to execute arbitrary code within the kernel context (CVE-2021-29154).

KVM: SVM: load control fields from VMCB12 before checking them (CVE-2021-29657).

It also adds the following fixes:

• x86/fpu/64: Don't FNINIT in kernel_fpu_begin()
• Revert "iommu/amd: Fix performance counter initialization"
• iommu/amd: Remove performance counter pre-initialization test
• hwmon: (amd_energy) Add AMD family 19h model 30h x86 match
• hwmon: (amd_energy) Use unified function to read energy data
• hwmon: (amd_energy) Restore visibility of energy counters

For other upstream fixes, see the referenced changelogs.

Ryota Shiga discovered that the eBPF implementation in the Linux kernel did not properly verify that a BPF program only reserved as much memory for a ring buffer as was allocated. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2021-3489)

Manfred Paul discovered that the eBPF implementation in the Linux kernel did not properly track bounds on bitwise operations. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2021-3490)

Billy Jheng Bing-Jhong discovered that the io_uring implementation of the Linux kernel did not properly enforce the MAX_RW_COUNT limit in some situations. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2021-3491)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the Linux kernel contained a reference counting error. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-25670)

Kiyin (尹亮) discovered that the NFC LLCP protocol implementation in the Linux kernel did not properly deallocate memory in certain error situations. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2020-25671, CVE-2020-25672)

It was discovered that the Xen paravirtualization backend in the Linux kernel did not properly deallocate memory in some situations. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2021-28688)

It was discovered that the io_uring subsystem in the Linux kernel contained a race condition leading to a deadlock condition. A local attacker could use this to cause a denial of service. (CVE-2021-28951)

John Stultz discovered that the audio driver for Qualcomm SDM845 systems in the Linux kernel did not properly validate port ID numbers. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-28952)

Zygo Blaxell discovered that the btrfs file system implementation in the Linux kernel contained a race condition during certain cloning operations. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-28964)

Vince Weaver discovered that the perf subsystem in the Linux kernel did not properly handle certain PEBS records properly for some Intel Haswell processors. A local attacker could use this to cause a denial of service (system crash). (CVE-2021-28971)

It was discovered that the RPA PCI Hotplug driver implementation in the Linux kernel did not properly handle device name writes via sysfs, leading to a buffer overflow. A privileged attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-28972)

It was discovered that the Freescale Gianfar Ethernet driver for the Linux kernel did not properly handle receive queue overrun when jumbo frames were enabled in some situations. An attacker could use this to cause a denial of service (system crash). (CVE-2021-29264)

It was discovered that the vDPA backend virtio driver in the Linux kernel contained a use-after-free vulnerability. An attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-29266)

It was discovered that the TIPC protocol implementation in the Linux kernel did not properly validate passed encryption key sizes. A local attacker could use this to cause a denial of service (system crash). (CVE-2021-29646)

It was discovered that the Qualcomm IPC router implementation in the Linux kernel did not properly initialize memory passed to user space. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2021-29647)

It was discovered that the BPF user mode driver implementation in the Linux kernel did not properly deallocate memory in some situations. A local attacker could use this to cause a denial of service…