commit 2a59239b22e0a39736b47c22462b3faa2c46b729 Author: Greg Kroah-Hartman Date: Thu Jun 16 13:28:00 2022 +0200 Linux 5.10.123 Link: https://lore.kernel.org/r/20220614183719.878453780@linuxfoundation.org Tested-by: Florian Fainelli Tested-by: Shuah Khan Tested-by: Fox Chen Tested-by: Sudip Mukherjee Tested-by: Linux Kernel Functional Testing Tested-by: Guenter Roeck Tested-by: Hulk Robot Tested-by: Tyler Hicks Tested-by: Salvatore Bonaccorso Tested-by: Jon Hunter Tested-by: Pavel Machek (CIP) Signed-off-by: Greg Kroah-Hartman commit aa238a92cc94a15812c0de4adade86ba8f22707a Author: Josh Poimboeuf Date: Mon May 23 09:11:49 2022 -0700 x86/speculation/mmio: Print SMT warning commit 1dc6ff02c8bf77d71b9b5d11cbc9df77cfb28626 upstream Similar to MDS and TAA, print a warning if SMT is enabled for the MMIO Stale Data vulnerability. Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit bde15fdcce44956278b4f50680b7363ca126ffb9 Author: Pawan Gupta Date: Thu May 19 20:35:15 2022 -0700 KVM: x86/speculation: Disable Fill buffer clear within guests commit 027bbb884be006b05d9c577d6401686053aa789e upstream The enumeration of MD_CLEAR in CPUID(EAX=7,ECX=0).EDX{bit 10} is not an accurate indicator on all CPUs of whether the VERW instruction will overwrite fill buffers. FB_CLEAR enumeration in IA32_ARCH_CAPABILITIES{bit 17} covers the case of CPUs that are not vulnerable to MDS/TAA, indicating that microcode does overwrite fill buffers. Guests running in VMM environments may not be aware of all the capabilities/vulnerabilities of the host CPU. Specifically, a guest may apply MDS/TAA mitigations when a virtual CPU is enumerated as vulnerable to MDS/TAA even when the physical CPU is not. On CPUs that enumerate FB_CLEAR_CTRL the VMM may set FB_CLEAR_DIS to skip overwriting of fill buffers by the VERW instruction. This is done by setting FB_CLEAR_DIS during VMENTER and resetting on VMEXIT. For guests that enumerate FB_CLEAR (explicitly asking for fill buffer clear capability) the VMM will not use FB_CLEAR_DIS. Irrespective of guest state, host overwrites CPU buffers before VMENTER to protect itself from an MMIO capable guest, as part of mitigation for MMIO Stale Data vulnerabilities. Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit 6df693dca31218f76c63b6fd4aa7b7db3bd6e049 Author: Pawan Gupta Date: Thu May 19 20:34:14 2022 -0700 x86/speculation/mmio: Reuse SRBDS mitigation for SBDS commit a992b8a4682f119ae035a01b40d4d0665c4a2875 upstream The Shared Buffers Data Sampling (SBDS) variant of Processor MMIO Stale Data vulnerabilities may expose RDRAND, RDSEED and SGX EGETKEY data. Mitigation for this is added by a microcode update. As some of the implications of SBDS are similar to SRBDS, SRBDS mitigation infrastructure can be leveraged by SBDS. Set X86_BUG_SRBDS and use SRBDS mitigation. Mitigation is enabled by default; use srbds=off to opt-out. Mitigation status can be checked from below file: /sys/devices/system/cpu/vulnerabilities/srbds Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit cf1c01a5e4c3e269b9211ae2ef0a57f8c9474bfc Author: Pawan Gupta Date: Thu May 19 20:33:13 2022 -0700 x86/speculation/srbds: Update SRBDS mitigation selection commit 22cac9c677c95f3ac5c9244f8ca0afdc7c8afb19 upstream Currently, Linux disables SRBDS mitigation on CPUs not affected by MDS and have the TSX feature disabled. On such CPUs, secrets cannot be extracted from CPU fill buffers using MDS or TAA. Without SRBDS mitigation, Processor MMIO Stale Data vulnerabilities can be used to extract RDRAND, RDSEED, and EGETKEY data. Do not disable SRBDS mitigation by default when CPU is also affected by Processor MMIO Stale Data vulnerabilities. Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit 001415e4e626403c9ff35f2498feb0021d0c8328 Author: Pawan Gupta Date: Thu May 19 20:32:13 2022 -0700 x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data commit 8d50cdf8b8341770bc6367bce40c0c1bb0e1d5b3 upstream Add the sysfs reporting file for Processor MMIO Stale Data vulnerability. It exposes the vulnerability and mitigation state similar to the existing files for the other hardware vulnerabilities. Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit 3eb1180564fa0ecedc33b44029da7687c0a9fbf5 Author: Pawan Gupta Date: Thu May 19 20:31:12 2022 -0700 x86/speculation/mmio: Enable CPU Fill buffer clearing on idle commit 99a83db5a605137424e1efe29dc0573d6a5b6316 upstream When the CPU is affected by Processor MMIO Stale Data vulnerabilities, Fill Buffer Stale Data Propagator (FBSDP) can propagate stale data out of Fill buffer to uncore buffer when CPU goes idle. Stale data can then be exploited with other variants using MMIO operations. Mitigate it by clearing the Fill buffer before entering idle state. Signed-off-by: Pawan Gupta Signed-off-by: Thomas Gleixner Co-developed-by: Josh Poimboeuf Signed-off-by: Josh Poimboeuf Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit 56f0bca5e9c8456b7bb7089cbb6de866a9ba6da9 Author: Pawan Gupta Date: Thu May 19 20:30:12 2022 -0700 x86/bugs: Group MDS, TAA & Processor MMIO Stale Data mitigations commit e5925fb867290ee924fcf2fe3ca887b792714366 upstream MDS, TAA and Processor MMIO Stale Data mitigations rely on clearing CPU buffers. Moreover, status of these mitigations affects each other. During boot, it is important to maintain the order in which these mitigations are selected. This is especially true for md_clear_update_mitigation() that needs to be called after MDS, TAA and Processor MMIO Stale Data mitigation selection is done. Introduce md_clear_select_mitigation(), and select all these mitigations from there. This reflects relationships between these mitigations and ensures proper ordering. Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit 26f6f231f6a5a79ccc274967939b22602dec76e8 Author: Pawan Gupta Date: Thu May 19 20:29:11 2022 -0700 x86/speculation/mmio: Add mitigation for Processor MMIO Stale Data commit 8cb861e9e3c9a55099ad3d08e1a3b653d29c33ca upstream Processor MMIO Stale Data is a class of vulnerabilities that may expose data after an MMIO operation. For details please refer to Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst. These vulnerabilities are broadly categorized as: Device Register Partial Write (DRPW): Some endpoint MMIO registers incorrectly handle writes that are smaller than the register size. Instead of aborting the write or only copying the correct subset of bytes (for example, 2 bytes for a 2-byte write), more bytes than specified by the write transaction may be written to the register. On some processors, this may expose stale data from the fill buffers of the core that created the write transaction. Shared Buffers Data Sampling (SBDS): After propagators may have moved data around the uncore and copied stale data into client core fill buffers, processors affected by MFBDS can leak data from the fill buffer. Shared Buffers Data Read (SBDR): It is similar to Shared Buffer Data Sampling (SBDS) except that the data is directly read into the architectural software-visible state. An attacker can use these vulnerabilities to extract data from CPU fill buffers using MDS and TAA methods. Mitigate it by clearing the CPU fill buffers using the VERW instruction before returning to a user or a guest. On CPUs not affected by MDS and TAA, user application cannot sample data from CPU fill buffers using MDS or TAA. A guest with MMIO access can still use DRPW or SBDR to extract data architecturally. Mitigate it with VERW instruction to clear fill buffers before VMENTER for MMIO capable guests. Add a kernel parameter mmio_stale_data={off|full|full,nosmt} to control the mitigation. Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit f83d4e5be4a3955a6c8af61ecec0934d0ece40c0 Author: Pawan Gupta Date: Thu May 19 20:28:10 2022 -0700 x86/speculation: Add a common function for MD_CLEAR mitigation update commit f52ea6c26953fed339aa4eae717ee5c2133c7ff2 upstream Processor MMIO Stale Data mitigation uses similar mitigation as MDS and TAA. In preparation for adding its mitigation, add a common function to update all mitigations that depend on MD_CLEAR. [ bp: Add a newline in md_clear_update_mitigation() to separate statements better. ] Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit e66310bc96b74ed3df9993e5d835ef3084d62048 Author: Pawan Gupta Date: Thu May 19 20:27:08 2022 -0700 x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug commit 51802186158c74a0304f51ab963e7c2b3a2b046f upstream Processor MMIO Stale Data is a class of vulnerabilities that may expose data after an MMIO operation. For more details please refer to Documentation/admin-guide/hw-vuln/processor_mmio_stale_data.rst Add the Processor MMIO Stale Data bug enumeration. A microcode update adds new bits to the MSR IA32_ARCH_CAPABILITIES, define them. Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman commit f8a85334a57e7842320476ff27be3a5f151da364 Author: Pawan Gupta Date: Thu May 19 20:26:07 2022 -0700 Documentation: Add documentation for Processor MMIO Stale Data commit 4419470191386456e0b8ed4eb06a70b0021798a6 upstream Add the admin guide for Processor MMIO stale data vulnerabilities. Signed-off-by: Pawan Gupta Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman