CVE-2021-4206

A flaw was found in the QXL display device emulation in QEMU. An integer overflow in the cursor_alloc() function can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. This flaw allows a malicious privileged guest user to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.

A flaw was found in the QXL display device emulation in QEMU. An integer overflow in the cursor_alloc() function can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. This flaw allows a malicious privileged guest user to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.

QEMU is a FAST! processor emulator using dynamic translation to achieve good emulation speed.

Security Fix(es):

A flaw was found in the QXL display device emulation in QEMU. An integer overflow in the cursor_alloc() function can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. This flaw allows a malicious privileged guest user to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.(CVE-2021-4206)

A flaw was found in the QXL display device emulation in QEMU. A double fetch of guest controlled values cursor->header.width and cursor->header.height can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. A malicious privileged guest user could use this flaw to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.(CVE-2021-4207)

A NULL pointer dereference flaw was found in the floppy disk emulator of QEMU. This issue occurs while processing read/write ioport commands if the selected floppy drive is not initialized with a block device. This flaw allows a privileged guest user to crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.(CVE-2021-20196)

A flaw was found in the virtio-net device of QEMU. This flaw was inadvertently introduced with the fix for CVE-2021-3748, which forgot to unmap the cached virtqueue elements on error, leading to memory leakage and other unexpected results. Affected QEMU version: 6.2.0.(CVE-2022-26353)

A flaw was found in the vhost-vsock device of QEMU. In case of error, an invalid element was not detached from the virtqueue before freeing its memory, leading to memory leakage and other unexpected results. Affected QEMU versions <= 6.2.0.(CVE-2022-26354)

Kernel-based Virtual Machine (KVM) offers a full virtualization solution for Linux on numerous hardware platforms. The virt:Rocky Linux module contains packages which provide user-space components used to run virtual machines using KVM. The packages also provide APIs for managing and interacting with the virtualized systems.

Security Fix(es):

• QEMU: QXL: integer overflow in cursor_alloc() can lead to heap buffer overflow (CVE-2021-4206)

• QEMU: QXL: double fetch in qxl_cursor() can lead to heap buffer overflow (CVE-2021-4207)

• QEMU: virtio-net: map leaking on error during receive (CVE-2022-26353)

• QEMU: vhost-vsock: missing virtqueue detach on error can lead to memory leak (CVE-2022-26354)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Bug Fix(es):

• Rocky Linux 9.0 guest with vsock device migration failed from Rocky Linux 9.0 > Rocky Linux 8.6 (BZ#2071103)

• Fail to rebuild the reference count tables of qcow2 image on host block devices (e.g. LVs) (BZ#2072242)

• Remove upstream-only devices from the qemu-kvm binary (BZ#2077928)

• When doing a cpu-baseline between skylake and cascadelake, cascadelake is selected as baseline. (BZ#2084030)

• Virt-v2v can't convert Rocky Linux8.6 guest from VMware on Rocky Linux8.6 (BZ#2093415)

Enhancement(s):

• Allow memory prealloc from multiple threads (BZ#2075569)

A flaw was found in the QXL display device emulation in QEMU. An integer overflow in the cursor_alloc() function can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. This flaw allows a malicious privileged guest user to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.

Kernel-based Virtual Machine (KVM) offers a full virtualization solution for Linux on numerous hardware platforms. The virt:rhel module contains packages which provide user-space components used to run virtual machines using KVM. The packages also provide APIs for managing and interacting with the virtualized systems. Security Fix(es):

• QEMU: QXL: integer overflow in cursor_alloc() can lead to heap buffer overflow (CVE-2021-4206)
• QEMU: QXL: double fetch in qxl_cursor() can lead to heap buffer overflow (CVE-2021-4207)
• QEMU: virtio-net: map leaking on error during receive (CVE-2022-26353)
• QEMU: vhost-vsock: missing virtqueue detach on error can lead to memory leak (CVE-2022-26354) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Bug Fix(es):
• AlmaLinux 9.0 guest with vsock device migration failed from AlmaLinux 9.0 > AlmaLinux 8.6 (BZ#2071103)
• Fail to rebuild the reference count tables of qcow2 image on host block devices (e.g. LVs) (BZ#2072242)
• Remove upstream-only devices from the qemu-kvm binary (BZ#2077928)
• When doing a cpu-baseline between skylake and cascadelake, cascadelake is selected as baseline. (BZ#2084030)
• Virt-v2v can't convert rhel8.6 guest from VMware on rhel8.6 (BZ#2093415) Enhancement(s):
• Allow memory prealloc from multiple threads (BZ#2075569)

These are all security issues fixed in the qemu-7.0.0-53.1 package on the GA media of openSUSE Tumbleweed.

This update for qemu fixes the following issues:

• CVE-2022-26354: Fixed missing virtqueue detach on error can lead to memory leak (bsc#1198712)
• CVE-2021-4207: Fixed double fetch in qxl_cursor() can lead to heap buffer overflow (bsc#1198037)
• CVE-2021-4206: Fixed integer overflow in cursor_alloc() can lead to heap buffer overflow (bsc#1198035)

This update for qemu fixes the following issues:

• CVE-2022-26354: Fixed missing virtqueue detach on error can lead to memory leak (bsc#1198712)
• CVE-2022-26353: Fixed map leaking on error during receive (bsc#1198711)
• CVE-2021-4207: Fixed double fetch in qxl_cursor() can lead to heap buffer overflow (bsc#1198037)
• CVE-2021-4206: Fixed integer overflow in cursor_alloc() can lead to heap buffer overflow (bsc#1198035)

This update for qemu fixes the following issues:

• CVE-2021-3409: Fixed an incomplete fix for CVE-2020-17380 and CVE-2020-25085 in sdhi controller. (bsc#1182282)
• CVE-2021-4206: Fixed an integer overflow in cursor_alloc which can lead to heap buffer overflow. (bsc#1198035)
• CVE-2021-4207: Fixed a double fetch in qxl_cursor ehich can lead to heap buffer overflow. (bsc#1198037)
• CVE-2022-0216: Fixed a use after free issue found in hw/scsi/lsi53c895a.c. (bsc#1198038)
• CVE-2022-35414: Fixed an uninitialized read during address translation that leads to a crash. (bsc#1201367)

This update for qemu fixes the following issues:

• CVE-2021-3409: Fixed an incomplete fix for CVE-2020-17380 and CVE-2020-25085 in sdhi controller. (bsc#1182282)
• CVE-2021-4206: Fixed an integer overflow in cursor_alloc which can lead to heap buffer overflow. (bsc#1198035)
• CVE-2021-4207: Fixed a double fetch in qxl_cursor ehich can lead to heap buffer overflow. (bsc#1198037)
• CVE-2022-0216: Fixed a use after free issue found in hw/scsi/lsi53c895a.c. (bsc#1198038)
• CVE-2022-35414: Fixed an uninitialized read during address translation that leads to a crash. (bsc#1201367)
• CVE-2021-3507: Fixed a heap buffer overflow in DMA read data transfers. (bsc#1185000)
• CVE-2020-17380: Fixed a heap buffer overflow in sdhci_sdma_transfer_multi_blocks. (bsc#1175144)

This update for qemu fixes the following issues:

• bsc#1172033 (CVE-2020-13253)

• bsc#1180207 (CVE-2020-14394)

• bsc#1172382 (CVE-2020-13754)

• bsc#1198038 (CVE-2022-0216)

• bsc#1193880 (CVE-2021-3929)

• bsc#1197653 (CVE-2022-1050)

• bsc#1205808 (CVE-2022-4144), bsc#1198712 (CVE-2022-26354)

• bsc#1175144 (CVE-2020-17380, CVE-2020-25085, CVE-2021-3409), bsc#1185000 (CVE-2021-3507), bsc#1201367, CVE-2022-35414

• About bsc#1175144, see also bsc#1182282 (CVE-2021-3409)

• bsc#1198035, CVE-2021-4206

This update for qemu fixes the following issues:

• CVE-2022-0216: Fixed a use-after-free in lsi_do_msgout() in hw/scsi/lsi53c895a.c (bsc#1198038).
• CVE-2021-3929: Fixed use-after-free in nvme, caused by DMA reentrancy issue (bsc#1193880).
• CVE-2021-4207: Fixed heap buffer overflow caused by double fetch in qxl_cursor() (bsc#1198037).
• CVE-2021-4206: Fixed integer overflow in cursor_alloc() (bsc#1198035).
• Amend .changes file: avoid declaring a still unfixed CVE, as fixed (bsc#1187529)
• Fix the build breaks caused by binutils update (bsc#1192463, bsc#1193621)

Alexander Bulekov discovered that QEMU incorrectly handled floppy disk emulation. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly leak sensitive information. (CVE-2021-3507)

It was discovered that QEMU incorrectly handled NVME controller emulation. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 22.04 LTS. (CVE-2021-3929)

It was discovered that QEMU incorrectly handled QXL display device emulation. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2021-4206, CVE-2021-4207)

Jietao Xiao, Jinku Li, Wenbo Shen, and Nanzi Yang discovered that QEMU incorrectly handled the virtiofsd shared file system daemon. An attacker inside the guest could use this issue to create files with incorrect ownership, possibly leading to privilege escalation. This issue only affected Ubuntu 22.04 LTS. (CVE-2022-0358)

It was discovered that QEMU incorrectly handled virtio-net devices. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2022-26353)

It was discovered that QEMU incorrectly handled vhost-vsock devices. A privileged attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2022-26354)