{
  "id": "openEuler-SA-2023-1144",
  "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2023-1144",
  "title": "An update for kernel is now available for openEuler-22.03-LTS",
  "severity": "High",
  "description": "The Linux Kernel, the operating system core itself.\r\n\r\nSecurity Fix(es):\r\n\r\nThere is a logic error in io_uring's implementation which can be used to trigger a use-after-free vulnerability leading to privilege escalation. In the io_prep_async_work function the assumption that the last io_grab_identity call cannot return false is not true, and in this case the function will use the init_cred or the previous linked requests identity to do operations instead of using the current identity. This can lead to reference counting issues causing use-after-free. We recommend upgrading past version 5.10.161.(CVE-2023-0240)\r\n\r\nA memory leak flaw and potential divide by zero and Integer overflow was found in the Linux kernel V4L2 and vivid test code functionality. This issue occurs when a user triggers ioctls, such as VIDIOC_S_DV_TIMINGS ioctl. This could allow a local user to crash the system if vivid test code enabled.(CVE-2023-0615)\r\n\r\nThe Linux kernel does not correctly mitigate SMT attacks, as discovered\nthrough a strange pattern in the kernel API using STIBP as a mitigation[1\n<https://docs.kernel.org/userspace-api/spec_ctrl.html>], leaving the\nprocess exposed for a short period of time after a syscall. The kernel also\ndoes not issue an IBPB immediately during the syscall.\nThe ib_prctl_set [2\n<https://elixir.bootlin.com/linux/v5.15.56/source/arch/x86/kernel/cpu/bugs.c#L1467>]function\nupdates the Thread Information Flags (TIFs) for the task and updates the\nSPEC_CTRL MSR on the function __speculation_ctrl_update [3\n<https://elixir.bootlin.com/linux/v5.15.56/source/arch/x86/kernel/process.c#L557>],\nbut the IBPB is only issued on the next schedule, when the TIF bits are\nchecked. This leaves the victim vulnerable to values already injected on\nthe BTB, prior to the prctl syscall.\nThe behavior is only corrected after a reschedule of the task happens.\nFurthermore, the kernel entrance (due to the syscall itself), does not\nissue an IBPB in the default scenarios (i.e., when the kernel protects\nitself via retpoline or eIBRS).(CVE-2023-0045)\r\n\r\nREMAP cmd of SVM driver can be used to remap read only memory as read-write, then cause read only memory/file modified..(CVE-2021-33639)",
  "cves": [
    {
      "id": "CVE-2021-33639",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-33639",
      "severity": "High"
    }
  ]
}