Unable to run `su` command directly in a shell

[Fede2782]

As a workaround you can run exec su or sh -c "su".

Please check before submitting an issue

• I have searched the issues and haven't found anything relevant
• I will upload bugreport file in KernelSU Manager - Settings - Report log
• I know how to reproduce the issue which may not be specific to my device

Describe the bug

Unable to use "su" command in adb shell or any other terminal app which doesn't have a wrapper for su.

To Reproduce

1. Open ADB shell, grant shell root permission via Manager
2. run 'su'

Expected behavior

"su" command should allow to obtain root access directly. Apps like Material Files are able to get root access properly.

Screenshots

Logs

KernelSU_bugreport_2025-06-21_22_14.tar.gz

Device info

• Device: a34x SM-A346B
• OS Version: Android 15
• KernelSU Version: v1.0.5, LKM mode
• Kernel Version: 6.6.50-android15-8, kernel image has been rebuilt to remove samsung knox features which interfere with root and KernelSU (UH,KDP,RKP,DEFEX,PROCA,FIVE,GAF)

Additional context

Manager, root access in Apps and Modules all work properly, only root in adb is broken. This also happens without any module installed of course.

[backslashxx]

does ls -la /system/bin/su show anything?

[Fede2782]

does ls -la /system/bin/su show anything?

From adb shell, it shows that nothing exists but I'm pretty sure that this is because "shell" user cannot access the bin folder of system

So, I tried to use Termux, which uses an included su binary to get root access and it was able to gain root access (of course after enabling it in Manager). I was then able to check the existence of /system/bin/su and confirmed that running it doesn't work.

Another Terminal app which doesn't ship a su binary behaves the same way as adb shell does. First two commands have been run with the Root Permission enabled in manager. While the last two have been run without the Root Permission enabled.

From these tests, I think there is some problem in KernelSU's sucompat.

[Fede2782]

does the same issue happen on GKI / kernel in-built?

A34 isn't GKI so I cannot use the pre built kernel images. I didn't try building the kernel with KernelSU integrated with KProbes, I might try later on after testing those 2 commits.

[Fede2782]

yeah go build integrated first (kprobes or manual hook) if it still fails then that really is an issue

I rather think this is an LKM issue. I was using KernelSU in KPROBES mode on this same device with its old 4.19 kernel and everything was working correctly.

In any case I started running the build with kprobes. I will keep you updated with the situation.

[Fede2782]

yeah go build integrated first (kprobes or manual hook) if it still fails then that really is an issue

I tried building with KernelSU integrated into kernel binary with kprobes and situation is still exactly the same. do you need some logs? do you want me to try a build with your patches for old armv8?

[Fede2782]

I guess you can try it.

No luck, still broken. Should I try integrating official or yours with manual hooks?

[Fede2782]

But apparently this is pretty similar to #1813. If I run "su" in the same shell using "exec" I can get root access without issues. So I guess there is some issue in the integration due to upstream linux changes.

[Fede2782]

I guess you can try it.

No luck, still broken. Should I try integrating official or yours with manual hooks?

try official first with manual hooks imo if official with manual hook fails then something really happened around here

backslashxx@939f0fb

^ try bruteforcing it with this change

Manual hooks both with my repo and official (v.0.9.5) made everything unbootable.

I will try with your change. I guess it requires also cherry picking a few previous commits to introduce is_access_ok. I still didn't check it but should it help address this issue or is just a continuation of the armv8 fixes, cause A34 isn't affected by that thing.

[Fede2782]

I guess you can try it.

No luck, still broken. Should I try integrating official or yours with manual hooks?

try official first with manual hooks imo if official with manual hook fails then something really happened around here

backslashxx@939f0fb

^ try bruteforcing it with this change

Tried and still broken. I will consider this as an occasion to update some details in the op.

[backslashxx]

@Fede2782 try
https://github.com/backslashxx/KernelSU/actions/runs/15818358593

[Fede2782]

It broke KernelSU root access completely apparently. I tried both your manager and official manager and both did the same error "Failed to grant root". I attached the bugreport but very likely is useless.

KernelSU_bugreport_2025-06-23_11_27.tar.gz

[backslashxx]

@Fede2782 how about https://github.com/backslashxx/KernelSU/actions/runs/15819943602

no need to use other managers, official should be fine