The current implementation of the prctl syscall does not issue an IBPB immediately during the syscall. The ib_prctl_set  function updates the Thread Information Flags (TIFs) for the task and updates the SPEC_CTRL MSR on the function __speculation_ctrl_update, but the IBPB is only issued on the next schedule, when the TIF bits are checked. This leaves the victim vulnerable to values already injected on the BTB, prior to the prctl syscall.  The patch that added the support for the conditional mitigation via prctl (ib_prctl_set) dates back to the kernel 4.9.176.

We recommend upgrading past commit a664ec9158eeddd75121d39c9a0758016097fa96

Zhenpeng Lin discovered that the network packet scheduler implementation in the Linux kernel did not properly remove all references to a route filter before freeing it in some situations. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. An issue was found in the Linux kernel in nf_conntrack_irc where the message handling can be confused and incorrectly matches the message. A firewall may be able to be bypassed when users are using unencrypted IRC with nf_conntrack_irc configured. A vulnerability was found in Linux Kernel. It has been declared as problematic. Affected by this vulnerability is the function ipv6_renew_options of the component IPv6 Handler. The manipulation leads to memory leak. The attack can be launched remotely. It is recommended to apply a patch to fix this issue. The identifier VDB-211021 was assigned to this vulnerability. A timing based side channel exists in the OpenSSL RSA Decryption implementation which could be sufficient to recover a plaintext across a network in a Bleichenbacher style attack. To achieve a successful decryption an attacker would have to be able to send a very large number of trial messages for decryption. The vulnerability affects all RSA padding modes: PKCS#1 v1.5, RSA-OEAP and RSASVE. For example, in a TLS connection, RSA is commonly used by a client to send an encrypted pre-master secret to the server. An attacker that had observed a genuine connection between a client and a se…

Affected: openEuler:20.03-LTS-SP3: kernel

The Linux Kernel, the operating system core itself. Security Fix(es): The Linux kernel does not correctly mitigate SMT attacks, as discovered through a strange pattern in the kernel API using STIBP as a mitigation[1 <https://docs.kernel.org/userspace-api/spec_ctrl.html>], leaving the process exposed for a short period of time after a syscall. The kernel also does not issue an IBPB immediately during the syscall. The ib_prctl_set [2 <https://elixir.bootlin.com/linux/v5.15.56/source/arch/x86/kernel/cpu/bugs.c#L1467>]function updates the Thread Information Flags (TIFs) for the task and updates the SPEC_CTRL MSR on the function __speculation_ctrl_update [3 <https://elixir.bootlin.com/linux/v5.15.56/source/arch/x86/kernel/process.c#L557>], but the IBPB is only issued on the next schedule, when the TIF bits are checked. This leaves the victim vulnerable to values already injected on the BTB, prior to the prctl syscall. The behavior is only corrected after a reschedule of the task happens. Furthermore, the kernel entrance (due to the syscall itself), does not issue an IBPB in the default scenarios (i.e., when the kernel protects itself via retpoline or eIBRS).(CVE-2023-0045) REMAP cmd of SVM driver can be used to remap read only memory as read-write, then cause read only memory/file modified..(CVE-2021-33639)

kernel-devel-6.1.12-1.1 on GA media

Security update for the Linux Kernel

Affected: Ubuntu:Pro:14.04:LTS: linux-aws, Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:14.04:LTS: linux-lts-xenial, Ubuntu:Pro:16.04:LTS: linux, Ubuntu:Pro:16.04:LTS: linux-aws, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe, Ubuntu:Pro:16.04:LTS: linux-kvm and 124 more

The current implementation of the prctl syscall does not issue an IBPB immediately during the syscall. The ib_prctl_set  function updates the Thread Information Flags (TIFs) for the task and updates the SPEC_CTRL MSR on the function __speculation_ctrl_update, but the IBPB is only issued on the next schedule, when the TIF bits are checked. This leaves the victim vulnerable to values already injected on the BTB, prior to the prctl syscall.  The patch that added the support for the conditional mitigation via prctl (ib_prctl_set) dates back to the kernel 4.9.176. We recommend upgrading past commit a664ec9158eeddd75121d39c9a0758016097fa96

Ein lokaler Angreifer kann eine Schwachstelle im Linux Kernel ausnutzen, um Sicherheitsvorkehrungen zu umgehen.