1. Release Notes for Unbreakable Enterprise Kernel Release 6 Update 3
  2. Security Fixes for CVEs

2 Security Fixes for CVEs

This chapter lists security vulnerabilities and exposures (CVEs) that are specifically addressed in this release. Note that CVEs are continually handled in patch updates that are made available as errata builds for the current release. For this reason, it is absolutely critical that you keep your system up to date with the latest package updates for this kernel release.

You can keep up to date with the latest CVE information at https://linux.oracle.com/cve.

List of CVEs fixed in this release

The following list describes the CVEs that are fixed in this release. The content provided here is automatically generated and includes the CVE identifier and a summary of the issue. The associated internal Oracle bug identifiers are also included to reference work that was carried out to address each issue.

  • CVE-2017-6074

    The dccp_rcv_state_process function in net/dccp/input.c in the Linux kernel through 4.9.11 mishandles DCCP_PKT_REQUEST packet data structures in the LISTEN state, which allows local users to obtain root privileges or cause a denial of service (double free) via an application that makes an IPV6_RECVPKTINFO setsockopt system call.A use-after-free flaw was found in the way the Linux kernel's Datagram Congestion Control Protocol (DCCP) implementation freed SKB (socket buffer) resources for a DCCP_PKT_REQUEST packet when the IPV6_RECVPKTINFO option is set on the socket. A local, unprivileged user could use this flaw to alter the kernel memory, allowing them to escalate their privileges on the system. (Bug: 33408808 )

    See https://linux.oracle.com/cve/CVE-2017-6074.html for more information.

  • CVE-2019-2308

    See https://linux.oracle.com/cve/CVE-2019-2308.html for more information.

  • CVE-2020-14304

    A memory disclosure flaw was found in the Linux kernel's ethernet drivers, in the way it read data from the EEPROM of the device. This flaw allows a local user to read uninitialized values from the kernel memory. The highest threat from this vulnerability is to confidentiality.A memory disclosure flaw was found in the Linux kernel's ethernet drivers, in the way it read data from the EEPROM of the device. This flaw allows a local user to read uninitialized values from the kernel memory. The highest threat from this vulnerability is to confidentiality. (Bug: 31895295 )

    See https://linux.oracle.com/cve/CVE-2020-14304.html for more information.

  • CVE-2020-16119

    Use-after-free vulnerability in the Linux kernel exploitable by a local attacker due to reuse of a DCCP socket with an attached dccps_hc_tx_ccid object as a listener after being released. Fixed in Ubuntu Linux kernel 5.4.0-51.56, 5.3.0-68.63, 4.15.0-121.123, 4.4.0-193.224, 3.13.0.182.191 and 3.2.0-149.196.A flaw was found in the Linux kernel. When reusing a socket with an attached dccps_hc_tx_ccid as a listener, the socket will be used after being released leading to denial of service (DoS) or a potential code execution. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (Bug: 33408808 )

  • CVE-2020-24586

    The 802.11 standard that underpins Wi-Fi Protected Access (WPA, WPA2, and WPA3) and Wired Equivalent Privacy (WEP) doesn't require that received fragments be cleared from memory after (re)connecting to a network. Under the right circumstances, when another device sends fragmented frames encrypted using WEP, CCMP, or GCMP, this can be abused to inject arbitrary network packets and/or exfiltrate user data.A flaw was found in the Linux kernels implementation of wifi fragmentation handling. An attacker with the ability to transmit within the wireless transmission range of an access point can abuse a flaw where previous contents of wifi fragments can be unintentionally transmitted to another device.

    See https://linux.oracle.com/cve/CVE-2020-24586.html for more information.

  • CVE-2020-24587

    The 802.11 standard that underpins Wi-Fi Protected Access (WPA, WPA2, and WPA3) and Wired Equivalent Privacy (WEP) doesn't require that all fragments of a frame are encrypted under the same key. An adversary can abuse this to decrypt selected fragments when another device sends fragmented frames and the WEP, CCMP, or GCMP encryption key is periodically renewed.A flaw was found in the Linux kernel's WiFi implementation. An attacker within the wireless range can abuse a logic flaw in the WiFi implementation by reassembling packets from multiple fragments under different keys, treating them as valid. This flaw allows an attacker to send a fragment under an incorrect key, treating them as a valid fragment under the new key. The highest threat from this vulnerability is to confidentiality.

    See https://linux.oracle.com/cve/CVE-2020-24587.html for more information.

  • CVE-2020-24588

    The 802.11 standard that underpins Wi-Fi Protected Access (WPA, WPA2, and WPA3) and Wired Equivalent Privacy (WEP) doesn't require that the A-MSDU flag in the plaintext QoS header field is authenticated. Against devices that support receiving non-SSP A-MSDU frames (which is mandatory as part of 802.11n), an adversary can abuse this to inject arbitrary network packets.A flaw was found in the Linux kernels wifi implementation. An attacker within wireless broadcast range can inject custom data into the wireless communication circumventing checks on the data. This can cause the frame to pass checks and be considered a valid frame of a different type.

    See https://linux.oracle.com/cve/CVE-2020-24588.html for more information.

  • CVE-2020-25670

    A vulnerability was found in Linux Kernel where refcount leak in llcp_sock_bind() causing use-after-free which might lead to privilege escalations.A use-after-free flaw was found in the Linux kernel’s NFC LLCP protocol implementation in the way the user performs manipulation with an unknown input for the llcp_sock_bind() function. This flaw allows a local user to crash or escalate their privileges on the system.

    See https://linux.oracle.com/cve/CVE-2020-25670.html for more information.

  • CVE-2020-25671

    A vulnerability was found in Linux Kernel, where a refcount leak in llcp_sock_connect() causing use-after-free which might lead to privilege escalations.A use-after-free flaw was found in the Linux kernel’s NFC LLCP protocol implementation in the way the user triggers the llcp_sock_connect() function. This flaw allows a local user to crash the system.

    See https://linux.oracle.com/cve/CVE-2020-25671.html for more information.

  • CVE-2020-25672

    A memory leak vulnerability was found in Linux kernel in llcp_sock_connectA memory leak in the Linux kernel’s NFC LLCP protocol implementation was found in the way a user triggers the llcp_sock_connect() function. This flaw allows a local user to starve the resources, causing a denial of service.

    See https://linux.oracle.com/cve/CVE-2020-25672.html for more information.

  • CVE-2020-26141

    An issue was discovered in the ALFA Windows 10 driver 6.1316.1209 for AWUS036H. The Wi-Fi implementation does not verify the Message Integrity Check (authenticity) of fragmented TKIP frames. An adversary can abuse this to inject and possibly decrypt packets in WPA or WPA2 networks that support the TKIP data-confidentiality protocol.A vulnerability was found in Linux kernel's WiFi implementation. An attacker within wireless range can inject a control packet fragment where the kernel does not verify the Message Integrity Check (authenticity) of fragmented TKIP frames.

    See https://linux.oracle.com/cve/CVE-2020-26141.html for more information.

  • CVE-2020-26145

    An issue was discovered on Samsung Galaxy S3 i9305 4.4.4 devices. The WEP, WPA, WPA2, and WPA3 implementations accept second (or subsequent) broadcast fragments even when sent in plaintext and process them as full unfragmented frames. An adversary can abuse this to inject arbitrary network packets independent of the network configuration.A flaw was found in ath10k_htt_rx_proc_rx_frag_ind_hl in drivers/net/wireless/ath/ath10k/htt_rx.c in the Linux kernel WiFi implementations, where it accepts a second (or subsequent) broadcast fragments even when sent in plaintext and then process them as full unfragmented frames. The highest threat from this vulnerability is to integrity.

    See https://linux.oracle.com/cve/CVE-2020-26145.html for more information.

  • CVE-2020-26147

    An issue was discovered in the Linux kernel 5.8.9. The WEP, WPA, WPA2, and WPA3 implementations reassemble fragments even though some of them were sent in plaintext. This vulnerability can be abused to inject packets and/or exfiltrate selected fragments when another device sends fragmented frames and the WEP, CCMP, or GCMP data-confidentiality protocol is used.A flaw was found in ieee80211_rx_h_defragment in net/mac80211/rx.c in the Linux Kernel's WiFi implementation. This vulnerability can be abused to inject packets or exfiltrate selected fragments when another device sends fragmented frames, and the WEP, CCMP, or GCMP data-confidentiality protocol is used. The highest threat from this vulnerability is to integrity.

    See https://linux.oracle.com/cve/CVE-2020-26147.html for more information.

  • CVE-2020-36310

    An issue was discovered in the Linux kernel before 5.8. arch/x86/kvm/svm/svm.c allows a set_memory_region_test infinite loop for certain nested page faults, aka CID-e72436bc3a52.A flaw was found in the Linux kernel. A nested page fault is created when an address does not have a memslot associated to it. The highest threat from this vulnerability is to system availability. This flaw can be triggered using a malformed Virtual Machine. When triggered this bug will lead to the user-space component of KVM to freeze. (Bug: 32759746 )

    See https://linux.oracle.com/cve/CVE-2020-36310.html for more information.

  • CVE-2020-36311

    An issue was discovered in the Linux kernel before 5.9. arch/x86/kvm/svm/sev.c allows attackers to cause a denial of service (soft lockup) by triggering destruction of a large SEV VM (which requires unregistering many encrypted regions), aka CID-7be74942f184.A flaw was found in the Linux kernel. This flaw allows attackers to cause a denial of service (soft lockup) by triggering the destruction of a large SEV VM, which requires unregistering many encrypted regions. The highest threat from this vulnerability is to system availability.

    See https://linux.oracle.com/cve/CVE-2020-36311.html for more information.

  • CVE-2021-22543

    An issue was discovered in Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users with the ability to start and control a VM to read/write random pages of memory and can result in local privilege escalation.A flaw was found in the Linux kernel’s KVM implementation, where improper handing of the VM_IO|VM_PFNMAP VMAs in KVM bypasses RO checks and leads to pages being freed while still accessible by the VMM and guest. This flaw allows users who can start and control a VM to read/write random pages of memory, resulting in local privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, and system availability.

    See https://linux.oracle.com/cve/CVE-2021-22543.html for more information.

  • CVE-2021-23133

    A race condition in Linux kernel SCTP sockets (net/sctp/socket.c) before 5.12-rc8 can lead to kernel privilege escalation from the context of a network service or an unprivileged process. If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock then an element is removed from the auto_asconf_splist list without any proper locking. This can be exploited by an attacker with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some SCTP socket.A use-after-free flaw was found in the Linux kernel's SCTP socket functionality that triggers a race condition. This flaw allows a local user to escalate their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (Bug: 32907967 )

    See https://linux.oracle.com/cve/CVE-2021-23133.html for more information.

  • CVE-2021-23134

    Use After Free vulnerability in nfc sockets in the Linux Kernel before 5.12.4 allows local attackers to elevate their privileges. In typical configurations, the issue can only be triggered by a privileged local user with the CAP_NET_RAW capability.A flaw was found in the Linux kernel. A use-after-free was found in the implementation of nfc sockets leading to a kernel privilege escalation from the context of an unprivileged user. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

    See https://linux.oracle.com/cve/CVE-2021-23134.html for more information.

  • CVE-2021-28038

    (Bug: 32651473 )

    See https://linux.oracle.com/cve/CVE-2021-28038.html for more information.

  • CVE-2021-28688

    (Bug: 32697850 )

    See https://linux.oracle.com/cve/CVE-2021-28688.html for more information.

  • CVE-2021-28950

    An issue was discovered in fs/fuse/fuse_i.h in the Linux kernel before 5.11.8. A "stall on CPU" can occur because a retry loop continually finds the same bad inode, aka CID-775c5033a0d1.A denial of service in the kernel side of the FUSE functionality can allow a local system to create a denial of service. (Bug: 32669269 )

    See https://linux.oracle.com/cve/CVE-2021-28950.html for more information.

  • CVE-2021-28964

    A race condition was discovered in get_old_root in fs/btrfs/ctree.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (BUG) because of a lack of locking on an extent buffer before a cloning operation, aka CID-dbcc7d57bffc.A race condition flaw was found in get_old_root in fs/btrfs/ctree.c in the Linux kernel in btrfs file-system. This flaw allows a local attacker with a special user privilege to cause a denial of service due to not locking an extent buffer before a cloning operation. The highest threat from this vulnerability is to system availability. (Bug: 32669450 )

    See https://linux.oracle.com/cve/CVE-2021-28964.html for more information.

  • CVE-2021-28971

    In intel_pmu_drain_pebs_nhm in arch/x86/events/intel/ds.c in the Linux kernel through 5.11.8 on some Haswell CPUs, userspace applications (such as perf-fuzzer) can cause a system crash because the PEBS status in a PEBS record is mishandled, aka CID-d88d05a9e0b6.A flaw was found in the Linux kernel. On some Haswell CPUs, userspace applications (such as perf-fuzzer) can cause a system crash because the PEBS status in a PEBS record is mishandled. (Bug: 32669468 )

    See https://linux.oracle.com/cve/CVE-2021-28971.html for more information.

  • CVE-2021-29154

    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. This affects arch/x86/net/bpf_jit_comp.c and arch/x86/net/bpf_jit_comp32.c.A flaw was found in the Linux kernels eBPF implementation. By default, accessing the eBPF verifier is only accessible to privileged users with CAP_SYS_ADMIN. A local user with the ability to insert eBPF instructions can abuse a flaw in eBPF to corrupt memory. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (Bug: 32759959 )

    See https://linux.oracle.com/cve/CVE-2021-29154.html for more information.

  • CVE-2021-29155

    An issue was discovered in the Linux kernel through 5.11.x. kernel/bpf/verifier.c performs undesirable out-of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory. Specifically, for sequences of pointer arithmetic operations, the pointer modification performed by the first operation is not correctly accounted for when restricting subsequent operations.A vulnerability was discovered in retrieve_ptr_limit in kernel/bpf/verifier.c in the Linux kernel mechanism to mitigate speculatively out-of-bounds loads (Spectre mitigation). In this flaw a local, special user privileged (CAP_SYS_ADMIN) BPF program running on affected systems may bypass the protection, and execute speculatively out-of-bounds loads from the kernel memory. This can be abused to extract contents of kernel memory via side-channel. (Bug: 32911979 )

    See https://linux.oracle.com/cve/CVE-2021-29155.html for more information.

  • CVE-2021-29266

    An issue was discovered in the Linux kernel before 5.11.9. drivers/vhost/vdpa.c has a use-after-free because v->config_ctx has an invalid value upon re-opening a character device, aka CID-f6bbf0010ba0.A flaw was found in the Linux kernel. An invalid value upon reopening a character device can cause a use-after-free memory corruption. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (Bug: 32696005 )

    See https://linux.oracle.com/cve/CVE-2021-29266.html for more information.

  • CVE-2021-29650

    An issue was discovered in the Linux kernel before 5.11.11. The netfilter subsystem allows attackers to cause a denial of service (panic) because net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h lack a full memory barrier upon the assignment of a new table value, aka CID-175e476b8cdf.A denial-of-service (DoS) flaw was identified in the Linux kernel due to an incorrect memory barrier in xt_replace_table in net/netfilter/x_tables.c in the netfilter subsystem. (Bug: 32709120 )

    See https://linux.oracle.com/cve/CVE-2021-29650.html for more information.

  • 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.A flaw was found in the Linux kernel. A KVM guest on AMD can launch a nested guest without the Intercept VMRUN control bit by exploiting a TOCTOU vulnerability in nested_svm_vmrun. A malicious guest could use this flaw to gain unrestricted access to host MSRs, possibly leading to guest-to-host escape scenario. (Bug: 32490237 )

  • CVE-2021-31829

    kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. Also, the BPF stack can contain uninitialized data that might represent sensitive information previously operated on by the kernel.A flaw was found in the Linux kernel's eBPF verification code. By default, accessing the eBPF verifier is only accessible to privileged users with CAP_SYS_ADMIN. This flaw allows a local user who can insert eBPF instructions, to use the eBPF verifier to abuse a spectre-like flaw and infer all system memory. The highest threat from this vulnerability is to confidentiality. (Bug: 32911990 )

    See https://linux.oracle.com/cve/CVE-2021-31829.html for more information.

  • CVE-2021-31916

    An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel before 5.12. A bound check failure allows an attacker with special user (CAP_SYS_ADMIN) privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability.An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel. A bound check failure allows an attacker with special user (CAP_SYS_ADMIN) privilege to gain access to out-of-bounds memory leading to a system crash, a leak of internal kernel information, or a privilege escalation problem. (Bug: 32860491 )

    See https://linux.oracle.com/cve/CVE-2021-31916.html for more information.

  • CVE-2021-32399

    net/bluetooth/hci_request.c in the Linux kernel through 5.12.2 has a race condition for removal of the HCI controller.A flaw was found in the Linux kernel’s handling of the removal of Bluetooth HCI controllers. This flaw allows an attacker with a local account to exploit a race condition, leading to corrupted memory and possible privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (Bug: 32912033 )

    See https://linux.oracle.com/cve/CVE-2021-32399.html for more information.

  • CVE-2021-33033

    The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd. This leads to writing an arbitrary value.A flaw use-after-free in the Linux kernel CIPSO network packet labeling protocol functionality was found in the way user open local network connection with the usage of the security labeling that is IP option number 134. A local user could use this flaw to crash the system or possibly escalate their privileges on the system. (Bug: 32912070 )

    See https://linux.oracle.com/cve/CVE-2021-33033.html for more information.

  • CVE-2021-33034

    In the Linux kernel before 5.12.4, net/bluetooth/hci_event.c has a use-after-free when destroying an hci_chan, aka CID-5c4c8c954409. This leads to writing an arbitrary value.A use-after-free flaw was found in hci_send_acl in the bluetooth host controller interface (HCI) in Linux kernel, where a local attacker with an access rights could cause a denial of service problem on the system The issue results from the object hchan, freed in hci_disconn_loglink_complete_evt, yet still used in other places. The highest threat from this vulnerability is to data integrity, confidentiality and system availability. (Bug: 32912099 )

    See https://linux.oracle.com/cve/CVE-2021-33034.html for more information.

  • CVE-2021-33909

    fs/seq_file.c in the Linux kernel 3.16 through 5.13.x before 5.13.4 does not properly restrict seq buffer allocations, leading to an integer overflow, an Out-of-bounds Write, and escalation to root by an unprivileged user, aka CID-8cae8cd89f05.An out-of-bounds write flaw was found in the Linux kernel's seq_file in the Filesystem layer. This flaw allows a local attacker with a user privilege to gain access to out-of-bound memory, leading to a system crash or a leak of internal kernel information. The issue results from not validating the size_t-to-int conversion prior to performing operations. The highest threat from this vulnerability is to data integrity, confidentiality and system availability. (Bug: 33135632 )

    See https://linux.oracle.com/cve/CVE-2021-33909.html for more information.

  • CVE-2021-3411

    A flaw was found in the Linux kernel in versions prior to 5.10. A violation of memory access was found while detecting a padding of int3 in the linking state. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.A flaw was found in the Linux kernel. A violation of memory access was found while detecting a padding of int3 in the linking state. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (Bug: 32576398 )

    See https://linux.oracle.com/cve/CVE-2021-3411.html for more information.

  • CVE-2021-3491

    The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being usedin mem_rw when reading /proc/<PID>/mem. This could be used to create a heap overflow leading to arbitrary code execution in the kernel. It was addressed via commit d1f82808877b ("io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers") (v5.13-rc1) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced in ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") (v5.7-rc1).A flaw was found in the Linux kernel. The io_uring PROVIDE_BUFFERS operation allowed the MAX_RW_COUNT limit to be bypassed, which led to negative values being used in mem_rw when reading /proc/<PID>/mem. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (Bug: 33042559 )

  • CVE-2021-3564

    A flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious HCI TTY Bluetooth device. A local user could use this flaw to crash the system. This flaw affects all the Linux kernel versions starting from 3.13.A flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious HCI TTY Bluetooth device. A local user could use this flaw to crash the system.

    See https://linux.oracle.com/cve/CVE-2021-3564.html for more information.

  • CVE-2021-3573

    A use-after-free in function hci_sock_bound_ioctl() of the Linux kernel HCI subsystem was found in the way user calls ioct HCIUNBLOCKADDR or other way triggers race condition of the call hci_unregister_dev() together with one of the calls hci_sock_blacklist_add(), hci_sock_blacklist_del(), hci_get_conn_info(), hci_get_auth_info(). A privileged local user could use this flaw to crash the system or escalate their privileges on the system. This flaw affects the Linux kernel versions prior to 5.13-rc5.A flaw use-after-free in function hci_sock_bound_ioctl() of the Linux kernel HCI subsystem was found in the way user calls ioct HCIUNBLOCKADDR or other way triggers race condition of the call hci_unregister_dev() together with one of the calls hci_sock_blacklist_add(), hci_sock_blacklist_del(), hci_get_conn_info(), hci_get_auth_info(). A privileged local user could use this flaw to crash the system or escalate their privileges on the system.

    See https://linux.oracle.com/cve/CVE-2021-3573.html for more information.

  • CVE-2021-3609

    A flaw was found in the CAN BCM networking protocol in the Linux kernel, where a local attacker can abuse a flaw in the CAN subsystem to corrupt memory, crash the system or escalate privileges. (Bug: 33114646 )

    See https://linux.oracle.com/cve/CVE-2021-3609.html for more information.

  • CVE-2021-3653

    A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "int_ctl" field, this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape. This flaw affects Linux kernel versions prior to 5.14-rc7.A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "int_ctl" field, this issue could allow a malicious L1 to enable AVIC support (Advanced Virtual Interrupt Controller) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape. (Bug: 33226010 33235071 )

    See https://linux.oracle.com/cve/CVE-2021-3653.html for more information.

  • CVE-2021-3656

    A flaw was found in the KVM's AMD code for supporting SVM nested virtualization. The flaw occurs when processing the VMCB (virtual machine control block) provided by the L1 guest to spawn/handle a nested guest (L2). Due to improper validation of the "virt_ext" field, this issue could allow a malicious L1 to disable both VMLOAD/VMSAVE intercepts and VLS (Virtual VMLOAD/VMSAVE) for the L2 guest. As a result, the L2 guest would be allowed to read/write physical pages of the host, resulting in a crash of the entire system, leak of sensitive data or potential guest-to-host escape. (Bug: 33235071 )

    See https://linux.oracle.com/cve/CVE-2021-3656.html for more information.

  • CVE-2021-37159

    hso_free_net_device in drivers/net/usb/hso.c in the Linux kernel through 5.13.4 calls unregister_netdev without checking for the NETREG_REGISTERED state, leading to a use-after-free and a double free.A flaw use-after-free in the Linux kernel USB High Speed Mobile Devices functionality was found in the way user detaches USB device. A local user could use this flaw to crash the system or escalate their privileges on the system. (Bug: 33329086 )

  • CVE-2021-3739

    A NULL pointer dereference flaw was found in the btrfs_rm_device function in fs/btrfs/volumes.c in the Linux Kernel, where triggering the bug requires ‘CAP_SYS_ADMIN’. This flaw allows a local attacker to crash the system or leak kernel internal information. The highest threat from this vulnerability is to system availability. (Bug: 33365609 )

    See https://linux.oracle.com/cve/CVE-2021-3739.html for more information.

  • CVE-2021-3743

    An out-of-bounds (OOB) memory read flaw was found in the Qualcomm IPC router protocol in the Linux kernel. A missing sanity check allows a local attacker to gain access to out-of-bounds memory, leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability. (Bug: 33336805 )

  • CVE-2021-38198

    arch/x86/kvm/mmu/paging_tmpl.h in the Linux kernel before 5.12.11 incorrectly computes the access permissions of a shadow page, leading to a missing guest protection page fault.A flaw was found in the Linux kernel, where it incorrectly computes the access permissions of a shadow page. This issue leads to a missing guest protection page fault. (Bug: 33359297 )

  • CVE-2021-40490

    A race condition was discovered in ext4_write_inline_data_end in fs/ext4/inline.c in the ext4 subsystem in the Linux kernel through 5.13.13.A flaw was found in the Linux kernel. A race condition was discovered in the ext4 subsystem. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (Bug: 33336785 )

    See https://linux.oracle.com/cve/CVE-2021-40490.html for more information.