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.

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.

This kernel update is based on upstream 5.10.27 and fixes at least the following security issues:

The fix for XSA-365 includes initialization of pointers such that subsequent cleanup code wouldn't use uninitialized or stale values. This initialization went too far and may under certain conditions also overwrite pointers which are in need of cleaning up. The lack of cleanup would result in leaking persistent grants. The leak in turn would prevent fully cleaning up after a respective guest has died, leaving around zombie domains. A malicious or buggy frontend driver may be able to cause resource leaks from the corresponding backend driver. This can result in a host-wide Denial of Sevice (DoS). (CVE-2021-28688 / XSA-371).

An issue was discovered in fs/io_uring.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (deadlock) because exit may be waiting to park a SQPOLL thread, but concurrently that SQPOLL thread is waiting for a signal to start (CVE-2021-28951).

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 (CVE-2021-28964).

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 (CVE-2021-28971).

In drivers/pci/hotplug/rpadlpar_sysfs.c in the Linux kernel through 5.11.8, the RPA PCI Hotplug driver has a user-tolerable buffer overflow when writing a new device name to the driver from userspace, allowing userspace to write data to the kernel stack frame directly. This occurs because add_slot_store and remove_slot_store mishandle drc_name '\0' termination (CVE-2021-28972).

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 (CVE-2021-29266).

It also adds the following fixes:

• arm: enable OF_OVERLAY (mga#28596)
• iomap: Fix negative assignment to unsigned sis->pages in iomap_swapfile_activate
• thermal/core: Add NULL pointer check before using cooling device stats

For other upstream fixes, see the referenced changelogs.

This kernel-linus update is based on upstream 5.10.27 and fixes at least the following security issues:

The fix for XSA-365 includes initialization of pointers such that subsequent cleanup code wouldn't use uninitialized or stale values. This initialization went too far and may under certain conditions also overwrite pointers which are in need of cleaning up. The lack of cleanup would result in leaking persistent grants. The leak in turn would prevent fully cleaning up after a respective guest has died, leaving around zombie domains. A malicious or buggy frontend driver may be able to cause resource leaks from the corresponding backend driver. This can result in a host-wide Denial of Sevice (DoS). (CVE-2021-28688 / XSA-371).

An issue was discovered in fs/io_uring.c in the Linux kernel through 5.11.8. It allows attackers to cause a denial of service (deadlock) because exit may be waiting to park a SQPOLL thread, but concurrently that SQPOLL thread is waiting for a signal to start (CVE-2021-28951).

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 (CVE-2021-28964).

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 (CVE-2021-28971).

In drivers/pci/hotplug/rpadlpar_sysfs.c in the Linux kernel through 5.11.8, the RPA PCI Hotplug driver has a user-tolerable buffer overflow when writing a new device name to the driver from userspace, allowing userspace to write data to the kernel stack frame directly. This occurs because add_slot_store and remove_slot_store mishandle drc_name '\0' termination (CVE-2021-28972).

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 (CVE-2021-29266).

It also adds the following fixes:

• arm: enable OF_OVERLAY (mga#28596)

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…

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)

It was discovered that the Nouveau GPU driver in the Linux kernel did not properly handle error conditions in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-25639)

Olivier Benjamin, Norbert Manthey, Martin Mazein, and Jan H. Schönherr discovered that the Xen paravirtualization backend in the Linux kernel did not properly propagate errors to frontend drivers in some situations. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26930)

Jan Beulich discovered that multiple Xen backends in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26931)

It was discovered that the fastrpc driver in the Linux kernel did not prevent user space applications from sending kernel RPC messages. A local attacker could possibly use this to gain elevated privileges. (CVE-2021-28375)

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 USB/IP driver in the Linux kernel contained race conditions during the update of local and shared status. An attacker could use this to cause a denial of service (system crash). (CVE-2021-29265)

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 a race condition existed in the netfilter subsystem of the Linux kernel when replacing tables. A local attacker could use this to cause a denial of service (system crash). (CVE-2021-29650)