CVE-2020-28588

An information disclosure vulnerability exists in the /proc/pid/syscall functionality of Linux Kernel 5.1 Stable and 5.4.66. More specifically, this issue has been introduced in v5.1-rc4 (commit 631b7abacd02b88f4b0795c08b54ad4fc3e7c7c0) and is still present in v5.10-rc4, so it’s likely that all versions in between are affected. An attacker can read /proc/pid/syscall to trigger this vulnerability, which leads to the kernel leaking memory contents.

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…

Bodong Zhao discovered a use-after-free in the Sun keyboard driver implementation in the Linux kernel. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2020-25669)

It was discovered that the jfs file system implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to possibly cause a denial of service (system crash). (CVE-2020-27815)

Shisong Qin and Bodong Zhao discovered that Speakup screen reader driver in the Linux kernel did not correctly handle setting line discipline in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-27830, CVE-2020-28941)

It was discovered that an information leak existed in the syscall implementation in the Linux kernel on 32 bit systems. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-28588)

Michael Kurth and Pawel Wieczorkiewicz discovered that the Xen event processing backend in the Linux kernel did not properly limit the number of events queued. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29568)

Olivier Benjamin and Pawel Wieczorkiewicz discovered a race condition the Xen paravirt block backend in the Linux kernel, leading to a use-after-free vulnerability. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29569)

Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-29660)

Jann Horn discovered a race condition in the tty subsystem of the Linux kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after- free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-29661)

It was discovered that the netfilter subsystem in the Linux kernel did not properly handle filter rules in some situations. A local attacker with the CAP_NET_ADMIN capability could use this to cause a denial of service. (CVE-2021-20177)

It was discovered that the console keyboard driver in the Linux kernel contained a race condition. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-25656)

Minh Yuan discovered that the tty driver in the Linux kernel contained race conditions when handling fonts. A local attacker could possibly use this to expose sensitive information (kernel memory). (CVE-2020-25668)

Bodong Zhao discovered a use-after-free in the Sun keyboard driver implementation in the Linux kernel. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2020-25669)

Kiyin (尹亮) discovered that the perf subsystem in the Linux kernel did not properly deallocate memory in some situations. A privileged attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2020-25704)

Julien Grall discovered that the Xen dom0 event handler in the Linux kernel did not properly limit the number of events queued. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-27673)

Jinoh Kang discovered that the Xen event channel infrastructure in the Linux kernel contained a race condition. An attacker in guest could possibly use this to cause a denial of service (dom0 crash). (CVE-2020-27675)

Daniel Axtens discovered that PowerPC RTAS implementation in the Linux kernel did not properly restrict memory accesses in some situations. A privileged local attacker could use this to arbitrarily modify kernel memory, potentially bypassing kernel lockdown restrictions. (CVE-2020-27777)

It was discovered that the jfs file system implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to possibly cause a denial of service (system crash). (CVE-2020-27815)

Shisong Qin and Bodong Zhao discovered that Speakup screen reader driver in the Linux kernel did not correctly handle setting line discipline in some situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-27830, CVE-2020-28941)

It was discovered that a use-after-free vulnerability existed in the infiniband hfi1 device driver in the Linux kernel. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2020-27835)

It was discovered that an information leak existed in the syscall implementation in the Linux kernel on 32 bit systems. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-28588)

Minh Yuan discovered that the framebuffer console driver in the Linux kernel did not properly handle fonts in some conditions. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-28974)

Michael Kurth and Pawel Wieczorkiewicz discovered that the Xen event processing backend in the Linux kernel did not properly limit the number of events queued. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29568)

Olivier Benjamin and Pawel Wieczorkiewicz discovered a race condition the Xen paravirt block backend in the Linux kernel, leading to a use-after-free vulnerability. An attacker in a guest VM could use this to cause a denial of service in the host OS. (CVE-2020-29569)

Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-29660)

Jann Horn discovered a race condition in the tty subsystem of the Linux kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after- free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-29661)

It was discovered that a…

Daniele Antonioli, Nils Ole Tippenhauer, and Kasper Rasmussen discovered that legacy pairing and secure-connections pairing authentication in the Bluetooth protocol could allow an unauthenticated user to complete authentication without pairing credentials via adjacent access. A physically proximate attacker could use this to impersonate a previously paired Bluetooth device. (CVE-2020-10135)

Jay Shin discovered that the ext4 file system implementation in the Linux kernel did not properly handle directory access with broken indexing, leading to an out-of-bounds read vulnerability. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-14314)

It was discovered that the block layer implementation in the Linux kernel did not properly perform reference counting in some situations, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash). (CVE-2020-15436)

It was discovered that the serial port driver in the Linux kernel did not properly initialize a pointer in some situations. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2020-15437)

Andy Nguyen discovered that the Bluetooth HCI event packet parser in the Linux kernel did not properly handle event advertisements of certain sizes, leading to a heap-based buffer overflow. A physically proximate remote attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-24490)

It was discovered that the NFS client implementation in the Linux kernel did not properly perform bounds checking before copying security labels in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-25212)

It was discovered that the Rados block device (rbd) driver in the Linux kernel did not properly perform privilege checks for access to rbd devices in some situations. A local attacker could use this to map or unmap rbd block devices. (CVE-2020-25284)

It was discovered that the block layer subsystem in the Linux kernel did not properly handle zero-length requests. A local attacker could use this to cause a denial of service. (CVE-2020-25641)

It was discovered that the HDLC PPP implementation in the Linux kernel did not properly validate input in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2020-25643)

Kiyin (尹亮) discovered that the perf subsystem in the Linux kernel did not properly deallocate memory in some situations. A privileged attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2020-25704)

It was discovered that the KVM hypervisor in the Linux kernel did not properly handle interrupts in certain situations. A local attacker in a guest VM could possibly use this to cause a denial of service (host system crash). (CVE-2020-27152)

It was discovered that the jfs file system implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to possibly cause a denial of service (system crash). (CVE-2020-27815)

It was discovered that an information leak existed in the syscall implementation in the Linux kernel on 32 bit systems. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-28588)

It was discovered that the framebuffer implementation in the Linux kernel did not properly perform range checks in certain situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-28915)

Jann Horn discovered a race condition in the copy-on-write implementation in the Linux kernel when handling hugepages. A local attacker could use this to gain unintended write access to read-only memory pages. (CVE-2020-29368)

Jann Horn discovered that the mmap implementation in the Linux kernel contained a race…