CVE-2021-3656 – kernel: SVM nested virtualization issue in KVM (VMLOAD/VMSAVE)
https://notcve.org/view.php?id=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. Se ha encontrado un fallo en el código AMD de KVM para soportar la virtualización anidada SVM. • https://github.com/rami08448/CVE-2021-3656-Demo https://bugzilla.redhat.com/show_bug.cgi?id=1983988 https://git.kernel.org/pub/scm/virt/kvm/kvm.git/commit/?id=c7dfa4009965a9b2d7b329ee970eb8da0d32f0bc https://github.com/torvalds/linux/commit/c7dfa4009965a9b2d7b329ee970eb8da0d32f0bc https://www.openwall.com/lists/oss-security/2021/08/16/1 https://access.redhat.com/security/cve/CVE-2021-3656 • CWE-862: Missing Authorization •
CVE-2021-3653 – kernel: SVM nested virtualization issue in KVM (AVIC support)
https://notcve.org/view.php?id=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. • http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html https://bugzilla.redhat.com/show_bug.cgi?id=1983686 https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html https://lists.debian.org/debian-lts-announce/2021/12/msg00012.html https://www.openwall.com/lists/oss-security/2021/08/16/1 https://access.redhat.com/security/cve/CVE-2021-3653 • CWE-862: Missing Authorization •
CVE-2021-40490
https://notcve.org/view.php?id=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. Se ha detectado una condición de carrera en la función ext4_write_inline_data_end en el archivo fs/ext4/inline.c en el subsistema ext4 en el kernel de Linux versiones hasta 5.13.13 • https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/commit/?id=9e445093e523f3277081314c864f708fd4bd34aa https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html https://lists.debian.org/debian-lts-announce/2021/12/msg00012.html https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M6VS2DLGT7TK7URKAS2KWJL3S533SGVA https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XJGX3DMJT6MRBW2XEF3TWVHYWZW3DG3N https://security.netapp.com/adv • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') •
CVE-2021-38198
https://notcve.org/view.php?id=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. El archivo arch/x86/kvm/mmu/paging_tmpl.h en el kernel de Linux versiones anteriores a 5.12.11, computa incorrectamente los permisos de acceso de una página sombra, conllevando a un fallo de página de protección de invitados • https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.11 https://github.com/torvalds/linux/commit/b1bd5cba3306691c771d558e94baa73e8b0b96b7 https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html https://lists.debian.org/debian-lts-announce/2021/12/msg00012.html •
CVE-2021-38199
https://notcve.org/view.php?id=CVE-2021-38199
fs/nfs/nfs4client.c in the Linux kernel before 5.13.4 has incorrect connection-setup ordering, which allows operators of remote NFSv4 servers to cause a denial of service (hanging of mounts) by arranging for those servers to be unreachable during trunking detection. El archivo fs/nfs/nfs4client.c en el kernel de Linux versiones anteriores a 5.13.4, presenta un ordenamiento incorrecto de la configuración de la conexión, que permite a operadores de servidores NFSv4 remotos causar una denegación de servicio (cuelgue de montajes) al disponer de que esos servidores sean inalcanzables durante la detección de trunking • https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.4 https://github.com/torvalds/linux/commit/dd99e9f98fbf423ff6d365b37a98e8879170f17c https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html https://lists.debian.org/debian-lts-announce/2021/12/msg00012.html https://security.netapp.com/advisory/ntap-20210902-0010 https://www.debian.org/security/2021/dsa-4978 •