current kernel from apt repo (6.16.8-edge-sunxi64) still vulnerable to local privilege escalation bug CVE-2026-31431 "copy.fail"

[akabulous]

Steps to repeat the bug:

1) use the cross platform PoC written in C, the Python one that everyone is sharing contains obfuscated code (bad ju-ju) and is x86_64 specific

`git clone https://github.com/tgies/copy-fail-c`

`cd copy-fail-c`

2) compile either on your target device natively, or do what I did and cross-compile it as a static binary using an aarch64-linux-musl toolchain (this made it easy to test on different SBCs)

`PREFIX="/opt/toolchains/aarch64-linux-musl-cross" CC=aarch64-linux-musl-gcc LD=aarch64-linux-musl-ld CFLAGS="-static -fPIC -I/opt/toolchains/aarch64-linux-musl-cross/include -L/opt/toolchains/aarch64-linux-musl-cross/lib" LDFLAGS="-static -fPIE -L/opt/toolchains/aarch64-linux-musl-cross/lib" make -j$(nproc --all)`

3) pass the resulting binaries "payload" and "exploit" to your target device (if you cross compiled)

4) from an unprivileged user account not in the sudo group, run the exploit

 

I'm not here to point fingers but I would like to see AT LEAST an advisory of this potentially devastating bug with a public exploit available on the Armbian homepage, radio silence for over a week seems completely inappropriate to me