chore: prepare for dev-build renaming to test-build

built from commit 295324a545
 dated 2026-03-31 19:34:52 +0200
 by Stéphane Lesimple (speed47_github@speed47.net)

.github/workflows/check.yml

@@ -0,0 +1,73 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: install prerequisites
+      run: sudo apt-get update && sudo apt-get install -y shellcheck jq sqlite3 iucode-tool
+    - name: shellcheck
+      run: shellcheck -s sh spectre-meltdown-checker.sh
+    - name: check indentation
+      run: |
+        if [ $(grep -cPv "^\t*\S|^$" spectre-meltdown-checker.sh) != 0 ]; then
+          echo "Badly indented lines found:"
+          grep -nPv "^\t*\S|^$" spectre-meltdown-checker.sh
+          exit 1
+        else
+          echo "Indentation seems correct."
+        fi
+    - name: check direct execution
+      run: |
+        expected=19
+        nb=$(sudo ./spectre-meltdown-checker.sh --batch json | jq '.[]|.CVE' | wc -l)
+        if [ "$nb" -ne "$expected" ]; then
+          echo "Invalid number of CVEs reported: $nb instead of $expected"
+          exit 1
+        else
+          echo "OK $nb CVEs reported"
+        fi
+    - name: check docker compose run execution
+      run: |
+        expected=19
+        docker compose build
+        nb=$(docker compose run --rm spectre-meltdown-checker --batch json | jq '.[]|.CVE' | wc -l)
+        if [ "$nb" -ne "$expected" ]; then
+          echo "Invalid number of CVEs reported: $nb instead of $expected"
+          exit 1
+        else
+          echo "OK $nb CVEs reported"
+        fi
+    - name: check docker run execution
+      run: |
+        expected=19
+        docker build -t spectre-meltdown-checker .
+        nb=$(docker run --rm --privileged -v /boot:/boot:ro -v /dev/cpu:/dev/cpu:ro -v /lib/modules:/lib/modules:ro spectre-meltdown-checker --batch json | jq '.[]|.CVE' | wc -l)
+        if [ "$nb" -ne "$expected" ]; then
+          echo "Invalid number of CVEs reported: $nb instead of $expected"
+          exit 1
+        else
+          echo "OK $nb CVEs reported"
+        fi
+    - name: check fwdb update
+      run: |
+        nbtmp1=$(find /tmp 2>/dev/null | wc -l)
+        ./spectre-meltdown-checker.sh --update-fwdb; ret=$?
+        if [ "$ret" != 0 ]; then
+          echo "Non-zero return value: $ret"
+          exit 1
+        fi
+        nbtmp2=$(find /tmp 2>/dev/null | wc -l)
+        if [ "$nbtmp1" != "$nbtmp2" ]; then
+          echo "Left temporary files!"
+          exit 1
+        fi
+        if ! [ -e ~/.mcedb ]; then
+          echo "No .mcedb file found after updating fwdb"
+          exit 1
+        fi

README.md

@@ -1,79 +1,34 @@
 Spectre & Meltdown Checker
 ==========================
 
-A self-contained shell script to assess your system's resilience against the several [transient execution](https://en.wikipedia.org/wiki/Transient_execution_CPU_vulnerability) CVEs that were published since early 2018, and give you guidance as to how to mitigate them.
+A shell script to assess your system's resilience against the several [transient execution](https://en.wikipedia.org/wiki/Transient_execution_CPU_vulnerability) CVEs that were published since early 2018, and give you guidance as to how to mitigate them.
 
-## CVE list
+CVE | Aliases | Impact | Mitigation | Perf. impact
-
+--- | ------- | ------ | ---------- | ------------
-CVE | Name | Aliases
+[CVE-2017-5753](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5753) | Spectre V1 | Kernel & all software | Recompile with LFENCE-inserting compiler | Negligible
---- | ---- | -------
+[CVE-2017-5715](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715) | Spectre V2 | Kernel | Microcode (IBRS) and/or retpoline | Medium to high
-[CVE-2017-5753](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5753) | Bounds Check Bypass | Spectre V1
+[CVE-2017-5754](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5754) | Meltdown | Kernel | Kernel update (PTI/KPTI) | Low to medium
-[CVE-2017-5715](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5715) | Branch Target Injection | Spectre V2
+[CVE-2018-3640](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3640) | Variant 3a | Kernel | Microcode update | Negligible
-[CVE-2017-5754](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5754) | Rogue Data Cache Load | Meltdown
+[CVE-2018-3639](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639) | Variant 4, SSB | JIT software | Microcode + kernel update | Low to medium
-[CVE-2018-3640](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3640) | Rogue System Register Read | Variant 3a
+[CVE-2018-3615](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3615) | Foreshadow (SGX) | SGX enclaves | Microcode update | Negligible
-[CVE-2018-3639](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3639) | Speculative Store Bypass | Variant 4, SSB
+[CVE-2018-3620](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3620) | Foreshadow-NG (OS/SMM) | Kernel & SMM | Kernel update (PTE inversion) | Negligible
-[CVE-2018-3615](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3615) | L1 Terminal Fault | Foreshadow (SGX)
+[CVE-2018-3646](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3646) | Foreshadow-NG (VMM) | VMM/hypervisors | Kernel update (L1d flush) or disable EPT/SMT | Low to significant
-[CVE-2018-3620](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3620) | L1 Terminal Fault | Foreshadow-NG (OS/SMM)
+[CVE-2018-12126](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12126) | MSBDS, Fallout | Kernel | Microcode + kernel update (MDS group) | Low to significant
-[CVE-2018-3646](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-3646) | L1 Terminal Fault | Foreshadow-NG (VMM)
+[CVE-2018-12130](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12130) | MFBDS, ZombieLoad | Kernel | Microcode + kernel update (MDS group) | Low to significant
-[CVE-2018-12126](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12126) | Microarchitectural Store Buffer Data Sampling | MSBDS, Fallout
+[CVE-2018-12127](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12127) | MLPDS, RIDL | Kernel | Microcode + kernel update (MDS group) | Low to significant
-[CVE-2018-12130](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12130) | Microarchitectural Fill Buffer Data Sampling | MFBDS, ZombieLoad
+[CVE-2019-11091](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-11091) | MDSUM, RIDL | Kernel | Microcode + kernel update (MDS group) | Low to significant
-[CVE-2018-12127](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12127) | Microarchitectural Load Port Data Sampling | MLPDS, RIDL
+[CVE-2019-11135](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-11135) | TAA, ZombieLoad V2 | Kernel | Microcode + kernel update | Low to significant
-[CVE-2019-11091](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-11091) | Microarchitectural Data Sampling Uncacheable Memory | MDSUM, RIDL
+[CVE-2018-12207](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12207) | iTLB Multihit, No eXcuses | VMM/hypervisors | Disable hugepages or update hypervisor | Low to significant
-[CVE-2019-11135](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-11135) | TSX Asynchronous Abort | TAA, ZombieLoad V2
+[CVE-2020-0543](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-0543) | SRBDS, CROSSTalk | All software (RDRAND/RDSEED) | Microcode + kernel update | Low
-[CVE-2018-12207](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12207) | Machine Check Exception on Page Size Changes | iTLB Multihit, No eXcuses
+[CVE-2022-40982](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-40982) | Downfall, GDS | Kernel & all software | Microcode update or disable AVX | Negligible to significant (AVX-heavy)
-[CVE-2020-0543](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-0543) | Special Register Buffer Data Sampling | SRBDS, CROSSTalk
+[CVE-2023-20569](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-20569) | Inception, SRSO | Kernel & all software | Kernel + microcode update | Low to significant
-[CVE-2022-40982](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-40982) | Gather Data Sampling | Downfall, GDS
+[CVE-2023-20593](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-20593) | Zenbleed | Kernel & all software | Kernel (MSR bit) or microcode update | Negligible
-[CVE-2023-20569](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-20569) | Return Address Security | Inception, SRSO
+[CVE-2023-23583](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-23583) | Reptar | All software | Microcode update | Low
-[CVE-2023-20593](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-20593) | Cross-Process Information Leak | Zenbleed
+[CVE-2024-36350](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-36350) | TSA-SQ | Kernel & all software (AMD) | Microcode + kernel update; SMT increases exposure | Low to medium
-[CVE-2023-23583](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-23583) | Redundant Prefix Issue | Reptar
+[CVE-2024-36357](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-36357) | TSA-L1 | Kernel & all software (AMD) | Microcode + kernel update | Low to medium
-[CVE-2024-36350](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-36350) | Transient Scheduler Attack, Store Queue | TSA-SQ
-[CVE-2024-36357](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-36357) | Transient Scheduler Attack, L1 | TSA-L1
-
-## Am I at risk?
-
-Depending on your situation, the table below answers whether an attacker in a given position can extract data from a given target.
-The "Userland → Kernel" column also applies within a VM (VM userland vs. VM kernel), since the same CPU mechanisms are at play regardless of virtualization.
-
-Vulnerability | Userland → Kernel | Userland → Userland | VM → Host | VM → VM | Mitigation
------------- | :---------------: | :-----------------: | :-------: | :-----: | ----------
-CVE-2017-5753 (Spectre V1) | 💥 | 💥 | 💥 | 💥 | Recompile everything with LFENCE
-CVE-2017-5715 (Spectre V2) | 💥 | 💥 | 💥 | 💥 | Microcode + kernel update (or retpoline)
-CVE-2017-5754 (Meltdown) | 💥 | ✅ | ✅ | ✅ | Kernel update
-CVE-2018-3640 (Variant 3a) | 💥 | ✅ | ✅ | ✅ | Microcode update
-CVE-2018-3639 (Variant 4, SSB) | ✅ | 💥 | ✅ | ✅ | Microcode + kernel update
-CVE-2018-3615 (Foreshadow, SGX) | ✅ (3) | ✅ (3) | ✅ (3) | ✅ (3) | Microcode update
-CVE-2018-3620 (Foreshadow-NG, OS/SMM) | 💥 | ✅ | ✅ | ✅ | Kernel update
-CVE-2018-3646 (Foreshadow-NG, VMM) | ✅ | ✅ | 💥 | 💥 | Kernel update (or disable EPT/SMT)
-CVE-2018-12126 (MSBDS, Fallout) | 💥 | 💥 (1) | 💥 | 💥 (1) | Microcode + kernel update
-CVE-2018-12130 (MFBDS, ZombieLoad) | 💥 | 💥 (1) | 💥 | 💥 (1) | Microcode + kernel update
-CVE-2018-12127 (MLPDS, RIDL) | 💥 | 💥 (1) | 💥 | 💥 (1) | Microcode + kernel update
-CVE-2019-11091 (MDSUM, RIDL) | 💥 | 💥 (1) | 💥 | 💥 (1) | Microcode + kernel update
-CVE-2019-11135 (TAA, ZombieLoad V2) | 💥 | 💥 (1) | 💥 | 💥 (1) | Microcode + kernel update
-CVE-2018-12207 (iTLB Multihit, No eXcuses) | ✅ | ✅ | ☠️ | ✅ | Hypervisor update (or disable hugepages)
-CVE-2020-0543 (SRBDS, CROSSTalk) | 💥 (2) | 💥 (2) | 💥 (2) | 💥 (2) | Microcode + kernel update
-CVE-2022-40982 (Downfall, GDS) | 💥 | 💥 | 💥 | 💥 | Microcode update (or disable AVX)
-CVE-2023-20569 (Inception, SRSO) | 💥 | ✅ | 💥 | ✅ | Microcode + kernel update
-CVE-2023-20593 (Zenbleed) | 💥 | 💥 | 💥 | 💥 | Microcode update (or kernel workaround)
-CVE-2023-23583 (Reptar) | ☠️ | ☠️ | ☠️ | ☠️ | Microcode update
-CVE-2024-36350 (TSA-SQ) | 💥 | 💥 (1) | 💥 | 💥 (1) | Microcode + kernel update
-CVE-2024-36357 (TSA-L1) | 💥 | 💥 (1) | 💥 | 💥 (1) | Microcode + kernel update
-
-> 💥 Data can be leaked across this boundary.
-
-> ✅ Not affected in this scenario.
-
-> ☠️ Denial of service (system crash or unpredictable behavior), no data leak.
-
-> (1) Cross-process leakage requires SMT (Hyper-Threading) to be active — attacker and victim must share a physical core.
-
-> (2) Only leaks RDRAND/RDSEED output, not arbitrary memory; still allows recovering cryptographic material from any victim.
-
-> (3) CVE-2018-3615 (Foreshadow SGX) inverts the normal trust model: the OS reads SGX enclave data. It is irrelevant unless the system runs SGX enclaves, and the attacker must already have OS-level access.
-
-## Detailed CVE descriptions
 
 <details>
-<summary>Unfold for more detailed CVE descriptions</summary>
+<summary>Detailed CVE descriptions</summary>
 
 **CVE-2017-5753 — Bounds Check Bypass (Spectre Variant 1)**
 
@@ -155,15 +110,13 @@ On AMD Zen 3 and Zen 4 processors, the CPU's transient scheduler may speculative
 
 </details>
 
-## Scope
-
 Supported operating systems:
 - Linux (all versions, flavors and distros)
 - FreeBSD, NetBSD, DragonFlyBSD and derivatives (others BSDs are [not supported](FAQ.md#which-bsd-oses-are-supported))
 
 For Linux systems, the tool will detect mitigations, including backported non-vanilla patches, regardless of the advertised kernel version number and the distribution (such as Debian, Ubuntu, CentOS, RHEL, Fedora, openSUSE, Arch, ...), it also works if you've compiled your own kernel. More information [here](FAQ.md#how-does-this-script-work).
 
-Other operating systems such as MacOS, Windows, ESXi, etc. [will never be supported](FAQ.md#why-is-my-os-not-supported).
+Other operating systems such as MacOS, Windows, ESXi, etc. [will most likely never be supported](FAQ.md#why-is-my-os-not-supported).
 
 Supported architectures:
 - `x86` (32 bits)
@@ -173,13 +126,15 @@ Supported architectures:
 
 ## Frequently Asked Questions (FAQ)
 
-What is the purpose of this tool? Why was it written? How can it be useful to me? How does it work? What can I expect from it?
+- What is the purpose of this tool?
+- Why was it written?
+- How can it be useful to me?
+- How does it work?
+- What can I expect from it?
 
 All these questions (and more) have detailed answers in the [FAQ](FAQ.md), please have a look!
 
-## Running the script
+## Easy way to run the script
-
-### Direct way (recommended)
 
 - Get the latest version of the script using `curl` *or* `wget`
 
@@ -201,12 +156,9 @@ chmod +x spectre-meltdown-checker.sh
 sudo ./spectre-meltdown-checker.sh
 ```
 
-### Using a docker container
+### Run the script in a docker container
 
-<details>
+#### With docker-compose
-<summary>Unfold for instructions</summary>
-
-Using `docker compose`:
 
 ```shell
 docker compose build
@@ -216,15 +168,13 @@ docker compose run --rm spectre-meltdown-checker
 Note that on older versions of docker, `docker-compose` is a separate command, so you might
 need to replace the two `docker compose` occurences above by `docker-compose`.
 
-Using `docker build` directly:
+#### Without docker-compose
 
 ```shell
 docker build -t spectre-meltdown-checker .
 docker run --rm --privileged -v /boot:/boot:ro -v /dev/cpu:/dev/cpu:ro -v /lib/modules:/lib/modules:ro spectre-meltdown-checker
 ```
 
-</details>
-
 ## Example of script output
 
 - Intel Haswell CPU running under Ubuntu 16.04 LTS