ctrl+c not working on root's BASH shell

[seffparker]

Problem description

As the title states, the ctrl+c interrupt doing nothing in BASH shells running as root user.

Tried all three methods, volkey+c, termux alt keyboard, hackers keyboard. None works in root's bash. There were no issues later, this only started recently.
All methods works in root's sh shell, and non-root's bash shell.

Tried termux builtin BASH (v5) and a third-party bash (v4). Same issue on both.

Trid toggling SeLinux, no luck.

Steps to reproduce
su as root user to a BASH (not sh) shell and run any command that require an interrupt or just type a command name without pressing ENTER key, and then hit ctrl+c

Expected behavior
ctrl+c send interrupt and leaves the process.

Additional information
$ termux-info
Updatable packages:
All packages up to date
Subscribed repositories:
https://dl.bintray.com/grimler/termux-root-packages-21 root/stable
https://termux.net stable/main
https://termux.net stable/main
System information:
Linux batmobile 4.9.112-perf-gf165f5d #1 SMP PREEMPT Wed Apr 3 16:46:50 WIB 2019 aarch64 Android
Termux-packages arch:
aarch64
Android version:
9
Device manufacturer:
Xiaomi
Device model:
POCO F1

[ghost]

What is output of stty -a command running as root ?

[ghost]

There were no issues later, this only started recently.
and a third-party bash (v4). Same issue on both.

This points that issue is not Termux-specific. Especially when you use old third-party bash version and it affected by same issue.

No changes were done in bash packages recently (just rebuild). Also, nothing was changed in terminal emulation.

[seffparker]

Why its closed? The issue started without modifying anything on the third-party bash, and affect both bash version including the lastest one comes with termux-app.

So, its not bash's version specific. Its bash as root user.

[seffparker]

What is output of stty -a command running as root ?

speed 38400 baud; rows 77; columns 106; line = 0;
intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>;
start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0;
-parenb -parodd -cmspar cs8 -hupcl -cstopb cread -clocal -crtscts
-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel
-iutf8
opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0
isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc```

[seffparker]

Forgot add. I use both versions of bash binaries within the termux itself via su -s /path/to/shell method

[Grimler91]

@seffparker try re-rooting/updating su. The problem probably lies in your su variant.

Does ctrl + c work from a su bash shell in other terminal apps?

[ghost]

intr = ^C;

Your stty output is correct so possible problems only:

• With su binary.

• With environment variables.

I suggest you to try command tsu instead of su -s /path/to/shell. Regular su binary resets environment variables by default which may cause issues.

[seffparker]

You guys are correct. I have exact issue on terminal elmulator too.

So, it must be with su as you stated. btw, I use latest Magisk 19.3