UPDATE:

Suspecting from the kernel (4.1 branch on official Kali BBB image) I built a new image using kali-arm-build-scripts (https://github.com/offensive-security/kali-arm-build-scripts ) but switching to kernel branch 4.9. I chose this because wifi injection patches already existed on kali for this kernel. The newly built image doesn't crash anymore, no crashes so far in 36 hours uptime. It could be a coincidence, but. . .
So I suggest bumping kernel version of bbb.sh from 4.1 to 4.9. FYI the build steps taken are almost the recommended in kali-arm-build-scripts, with following differences:

• Didn't used recommended gcc ( https://github.com/offensive-security/gcc-arm-linux-gnueabihf-4.7 ) since there is already a cross compiler in repo and I had that already installed, whichs happens to be gcc-arm-linux-gnueabihf package version 4:7.2.0-1d1.

• Didn't installed all build-deps packages, since *-multilib are not necessary for BBB.

• Just edited bbb.sh to change kernel version from 4.1 to 4.9, patch appended.

202c202
< git clone https://github.com/beagleboard/linux -b 4.1 --depth 1 ${basedir}/root/usr/src/kernel
---
> git clone https://github.com/beagleboard/linux -b 4.9 --depth 1 ${basedir}/root/usr/src/kernel
209c209
< patch -p1 --no-backup-if-mismatch < ${basedir}/../patches/kali-wifi-injection-4.1.patch
---
> patch -p1 --no-backup-if-mismatch < ${basedir}/../patches/kali-wifi-injection-4.9.patch

@threeway Please have a look at this bug.

Thank you so much for the report @pkreuzt!

Appreciate the reproduction steps, and observed the same things here.

In the future, you can also submit this as a pull request on the kali-arm-build-scripts but a patch here works just as well!

I'll push the updated patch shortly, and see about getting an updated image released soon!

Updated image is posted as 2018.2a

Thanks again for the report, the steps to reproduce were extremely helpful!