Samsung M30s (SM-M307FN) reboot issues

[M30sOwner]

Dear Samsung support,

I bought an M30s (SM-M307FN) in the early 2020 and it was working without problems for about 6 months. After some time, the phone started to reboot by itself many times a day. Usually when switching to or from the lock mode. More recently it started to reboot even more often while using different apps. The reboots were persistent across Android 9, 10 and 11.

This problem is well-known in the Samsung M30s community.

I did an investigation into this problem and found a solution that works for me. It's a purely software fix that could be introduced in an official software update.

The phone (SM-M307FN) has been rebooting due to a Linux kernel issue (a NULL pointer dereference in the task MMU code) which has been already patched a long time ago in the mainline Linux version. I am still running Android 10, because that's the latest version (M307FNXXU2BTC6) of the OS Samsung has released on their open-source portal. I used this source code to patch and rebuild the Linux kernel to prevent the issue from happening.

The fix is just two lines of code that need to be changed to prevent the reboots due to memory pressure.

Samsung's Android 11 still ships with the same old kernel version (4.14.62) as their Android 9 (4.14.62), released back in 2018. There might have been some fixes between 4.14.62-19694174 and 4.14.62-20748039 introduced by Samsung in the meantime.

Regardless, this fix is not part of the source code for M307FNXXU2BTC6 (linked above) that's been released by Samsung in June 2020. The fix is also not included in Samsung Android 11 releases for other M30s models. Therefore, it doesn't seem like Samsung is actually applying the latest fixes for the 4.14 branch.

Samsung: Please apply this fix to your Android kernels and push the update to your customers. Thank you!

References for the "fix NULL pointer deref in smaps_pte_range()" patch:

[4.19,248/361] mm: /proc/pid/smaps_rollup: fix NULL pointer deref in smaps_pte_range()

https://lore.kernel.org/patchwork/patch/1010971/

Backport to the 4.14 branch in 4.14.81 (2018-10-26):

https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux-stable/+blame/refs/tags/v4.14....

[Patrick]

Hello, good evening,

There are no developers on the forum😃
If you wanna reach them kindly send your report through Samsung Members / support / feedback.

[M30sOwner]

Hi Patrick,

thank you for the reply and directions. Could you please provide me the link to the Feedback section you mentioned? I have problems finding it.

I also looked at the Sitemap and couldn't find the "Feedback" page:

https://www.samsung.com/nl/info/sitemap/

Thank you.

[Patrick]

Just install the application from the Playstore, its called Samsung Members😀

[M30sOwner]

Playstore says my phone is not compatible 😅

https://play.google.com/store/apps/details?id=com.samsung.android.voc&hl=en&gl=US

[Patrick]

https://www.samsung.com/nl/members/

[M30sOwner]

Thank you. The page you linked provides a link to the app:

https://www.samsung.com/nl/members/app/

and then

http://apps.samsung.com/appquery/appDetail.as?appId=com.samsung.android.voc

However, after opening it (in the Netherlands), the page says:

Application not supported
This app is no longer available for purchase or is not supported in this country.

😬😄

[BruceH]

Hi @M30sOwner,

Welcome to the Community!

You could try to visit one of our service centers or use our pick-up service to get your phone checked: https://bit.ly/2r9D0B2

This is not a common issue, and I assume it has something to do with your device 👍

[foenix_kiev]

hi. M30sOwner - Respect Bro. I Have this problem too. device dont want power on(((( bootloop Samsung M30s Powered by Android. help me please - i am from Ukraine and cant go in Youre Service. Sorry for my bad english

[MartijnK]

Hi @foenix_kiev, good morning,

When you connect your phone to a computer, you can use SmartSwitch to recover your phone. For more information about SmartSwitch, go to https://bit.ly/3gP4hYm

A different option is the reset your phone back to the factory settings, for more information about this go to: https://bit.ly/2L2Ebwe

Keep us posted, please!

Kind regards, 

Martijn