CVE-2020-29534

An issue was discovered in the Linux kernel before 5.9.3. io_uring takes a non-refcounted reference to the files_struct of the process that submitted a request, causing execve() to incorrectly optimize unshare_fd(), aka CID-0f2122045b94.

This update provides an upgrade to the new upstream 5.10 longterm branch, currently based on 5.10.6, adding new features and new and improved hardware support.

This update also fixes at least the following security issues:

In binder_release_work of binder.c, there is a possible use-after-free due to improper locking. This could lead to local escalation of privilege in the kernel with no additional execution privileges needed. User interaction is not needed for exploitation (CVE-2020-0423).

In various methods of hid-multitouch.c, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation (CVE-2020-0465).

Insufficient access control in the Linux kernel driver for some Intel(R) Processors may allow an authenticated user to potentially enable information disclosure via local access (CVE-2020-8694).

A potential vulnerability in the AMD extension to Linux "hwmon" service may allow an attacker to use the Linux-based Running Average Power Limit (RAPL) interface to show various side channel attacks. In line with industry partners, AMD has updated the RAPL interface to require privileged access (CVE-2020-12912).

A use-after-free memory flaw was found in the perf subsystem allowing a local attacker with permission to monitor perf events to corrupt memory and possibly escalate privileges. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability (CVE-2020-14351).

A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality (CVE-2020-25656).

Linux kernel concurrency use-after-free in vt (CVE-2020-25668).

Linux Kernel use-after-free in sunkbd_reinit (CVE-2020-25669).

A flaw memory leak in the Linux kernel performance monitoring subsystem was found in the way if using PERF_EVENT_IOC_SET_FILTER. A local user could use this flaw to starve the resources causing denial of service (CVE-2020-25704).

A flaw in the way reply ICMP packets are limited in the Linux kernel functionality was found that allows to quickly scan open UDP ports. This flaw allows an off-path remote user to effectively bypassing source port UDP randomization. The highest threat from this vulnerability is to confidentiality and possibly integrity, because software that relies on UDP source port randomization are indirectly affected as well (CVE-2020-25705).

An issue was discovered in ioapic_lazy_update_eoi in arch/x86/kvm/ioapic.c in the Linux kernel before 5.9.2. It has an infinite loop related to improper interaction between a resampler and edge triggering (CVE-2020-27152).

An issue was discovered in the Linux kernel before 5.8.15. scalar32_min_max_or in kernel/bpf/verifier.c mishandles bounds tracking during use of 64-bit values (CVE-2020-27194).

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. Guest OS users can cause a denial of service (host OS hang) via a high rate of events to dom0 (CVE-2020-27673).

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. drivers/xen/events/events_base.c allows event-channel removal during the event-handling loop (a race condition). This can cause a use-after-free or NULL pointer dereference, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device (CVE-2020-27675).

A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1). There was a race problem in trace_open and resize of cpu buffer running parallely on different cpus, may cause a denial of service problem (DOS). This flaw could even allow a local attacker with special user privilege to a kernel information leak threat…

This update provides an upgrade to the new upstream 5.10 longterm branch, currently based on 5.10.6, adding new features and new and improved hardware support.

This update also fixes at least the following security issues:

In binder_release_work of binder.c, there is a possible use-after-free due to improper locking. This could lead to local escalation of privilege in the kernel with no additional execution privileges needed. User interaction is not needed for exploitation (CVE-2020-0423).

In various methods of hid-multitouch.c, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation (CVE-2020-0465).

Insufficient access control in the Linux kernel driver for some Intel(R) Processors may allow an authenticated user to potentially enable information disclosure via local access (CVE-2020-8694).

A potential vulnerability in the AMD extension to Linux "hwmon" service may allow an attacker to use the Linux-based Running Average Power Limit (RAPL) interface to show various side channel attacks. In line with industry partners, AMD has updated the RAPL interface to require privileged access (CVE-2020-12912).

A use-after-free memory flaw was found in the perf subsystem allowing a local attacker with permission to monitor perf events to corrupt memory and possibly escalate privileges. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability (CVE-2020-14351).

A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality (CVE-2020-25656).

Linux kernel concurrency use-after-free in vt (CVE-2020-25668).

Linux Kernel use-after-free in sunkbd_reinit (CVE-2020-25669).

A flaw memory leak in the Linux kernel performance monitoring subsystem was found in the way if using PERF_EVENT_IOC_SET_FILTER. A local user could use this flaw to starve the resources causing denial of service (CVE-2020-25704).

A flaw in the way reply ICMP packets are limited in the Linux kernel functionality was found that allows to quickly scan open UDP ports. This flaw allows an off-path remote user to effectively bypassing source port UDP randomization. The highest threat from this vulnerability is to confidentiality and possibly integrity, because software that relies on UDP source port randomization are indirectly affected as well (CVE-2020-25705).

An issue was discovered in ioapic_lazy_update_eoi in arch/x86/kvm/ioapic.c in the Linux kernel before 5.9.2. It has an infinite loop related to improper interaction between a resampler and edge triggering (CVE-2020-27152).

An issue was discovered in the Linux kernel before 5.8.15. scalar32_min_max_or in kernel/bpf/verifier.c mishandles bounds tracking during use of 64-bit values (CVE-2020-27194).

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. Guest OS users can cause a denial of service (host OS hang) via a high rate of events to dom0 (CVE-2020-27673).

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. drivers/xen/events/events_base.c allows event-channel removal during the event-handling loop (a race condition). This can cause a use-after-free or NULL pointer dereference, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device (CVE-2020-27675).

A use-after-free flaw was found in kernel/trace/ring_buffer.c in Linux kernel (before 5.10-rc1). There was a race problem in trace_open and resize of cpu buffer running parallely on different cpus, may cause a denial of service problem (DOS). This flaw could even allow a local attacker with special user privilege to a kernel information leak threat…

It was discovered that the AMD Running Average Power Limit (RAPL) driver in the Linux kernel did not properly restrict access to power data. A local attacker could possibly use this to expose sensitive information. (CVE-2020-12912)

Jann Horn discovered that the io_uring subsystem in the Linux kernel did not properly perform reference counting in some situations. A local attacker could use this to expose sensitive information or possibly escalate privileges. (CVE-2020-29534)