potentially unexpected fatal signal 11

[Wycleff]

Hi Guy's,
since the Upgrade to Asus-Merlin 384.19, I'm seeing the following Error in my Log.
Sometimes 2 times in an Hour and I don't know why its appearing.

Little Back history:
Upgraded to an AX-58U several Weeks ago and installed Merlin 384.18. Later Upgraded to 384.19. Then that Error appeared and I did everything from Scratch.
I even did a complete reset with NVRAM Erase via SSH and reverted it back in the GUI to factory default with initializing. Even reformatted the USB (JFFS) and reinstalled everything.
After that, the error did not appear for several Weeks.
But now I changed some Settings regarding Wi-Fi/LAN/DHCP and the Error reappeared again. Very frustrating.

I'm currently running the following Add-ons:
Diversion
Skynet
Flexqos
ntpMerlin

And everything is up to date. Maybe someone has a clue what's triggering this error.

Sep 20 22:09:08 kernel: potentially unexpected fatal signal 11.
Sep 20 22:09:08 kernel: CPU: 1 PID: 25831 Comm: dcd Tainted: P           O    4.1.52 #1
Sep 20 22:09:08 kernel: Hardware name: Generic DT based system
Sep 20 22:09:08 kernel: task: d2b3b800 ti: c939e000 task.ti: c939e000
Sep 20 22:09:08 kernel: PC is at 0xb6c5b39c
Sep 20 22:09:08 kernel: LR is at 0x1dd14
Sep 20 22:09:08 kernel: pc : [<b6c5b39c>]    lr : [<0001dd14>]    psr: 600f0010
Sep 20 22:09:08 kernel: sp : be97e968  ip : 000a2050  fp : b5cff024
Sep 20 22:09:08 kernel: r10: 000a23c4  r9 : b5cff918  r8 : 000a287c
Sep 20 22:09:08 kernel: r7 : b5cff950  r6 : 000a2876  r5 : 00000000  r4 : b5cff8fc
Sep 20 22:09:08 kernel: r3 : 00000000  r2 : be97e944  r1 : 0007d612  r0 : 00000000
Sep 20 22:09:08 kernel: Flags: nZCv  IRQs on  FIQs on  Mode USER_32  ISA ARM  Segment user
Sep 20 22:09:08 kernel: Control: 10c5387d  Table: 10db004a  DAC: 00000015
Sep 20 22:09:08 kernel: CPU: 1 PID: 25831 Comm: dcd Tainted: P           O    4.1.52 #1
Sep 20 22:09:08 kernel: Hardware name: Generic DT based system
Sep 20 22:09:08 kernel: [<c0026e60>] (unwind_backtrace) from [<c0022c38>] (show_stack+0x10/0x14)
Sep 20 22:09:08 kernel: [<c0022c38>] (show_stack) from [<c045237c>] (dump_stack+0x8c/0xa0)
Sep 20 22:09:08 kernel: [<c045237c>] (dump_stack) from [<c003aad4>] (get_signal+0x490/0x558)
Sep 20 22:09:08 kernel: [<c003aad4>] (get_signal) from [<c00221d0>] (do_signal+0xc8/0x3ac)
Sep 20 22:09:08 kernel: [<c00221d0>] (do_signal) from [<c0022658>] (do_work_pending+0x94/0xa4)
Sep 20 22:09:08 kernel: [<c0022658>] (do_work_pending) from [<c001f4cc>] (work_pending+0xc/0x20)

 

[Jeffrey Young]

I believe this is related to trend micro and is out of Merlin control.

Do a search for Dcd tainted. Seems to be a well known issue.

 

[Wycleff]

Thank you !
I disable the Trend Micro stuff and have an eye on the log in the next day's.

 

[ARKASHA]

Did someone see this error with 386.1?

Feb  5 18:23:11 kernel: potentially unexpected fatal signal 11.

 

[panni]

Did someone see this error with 386.1?

Feb  5 18:23:11 kernel: potentially unexpected fatal signal 11.

I'm seeing this in 386.2 beta 2 (AX-58U):

Mar 22 11:06:52 kernel: potentially unexpected fatal signal 11.
Mar 22 11:06:52 kernel: CPU: 1 PID: 21161 Comm: dcd Tainted: P O 4.1.52 #1
Mar 22 11:06:52 kernel: Hardware name: Generic DT based system
Mar 22 11:06:52 kernel: task: cfa3d000 ti: cf86a000 task.ti: cf86a000
Mar 22 11:06:52 kernel: PC is at 0xb6c8139c
Mar 22 11:06:52 kernel: LR is at 0x1dcd8
Mar 22 11:06:52 kernel: pc : [<b6c8139c>] lr : [<0001dcd8>] psr: 600b0010
Mar 22 11:06:52 kernel: sp : be8e48d8 ip : 000a2050 fp : b5fff024
Mar 22 11:06:52 kernel: r10: 000a23c4 r9 : b5fff940 r8 : 000a287c
Mar 22 11:06:52 kernel: r7 : b5fff978 r6 : 000a2876 r5 : 00000000 r4 : b5fff924
Mar 22 11:06:52 kernel: r3 : 00000000 r2 : be8e48b4 r1 : 0007d726 r0 : 00000000
Mar 22 11:06:52 kernel: Flags: nZCv IRQs on FIQs on Mode USER_32 ISA ARM Segment user
Mar 22 11:06:52 kernel: Control: 10c5387d Table: 0d2e404a DAC: 00000015
Mar 22 11:06:52 kernel: CPU: 1 PID: 21161 Comm: dcd Tainted: P O 4.1.52 #1
Mar 22 11:06:52 kernel: Hardware name: Generic DT based system
Mar 22 11:06:52 kernel: [<c0026fe0>] (unwind_backtrace) from [<c0022c38>] (show_stack+0x10/0x14)
Mar 22 11:06:52 kernel: [<c0022c38>] (show_stack) from [<c044fbf4>] (dump_stack+0x8c/0xa0)
Mar 22 11:06:52 kernel: [<c044fbf4>] (dump_stack) from [<c003ac4c>] (get_signal+0x490/0x558)
Mar 22 11:06:52 kernel: [<c003ac4c>] (get_signal) from [<c00221d0>] (do_signal+0xc8/0x3ac)
Mar 22 11:06:52 kernel: [<c00221d0>] (do_signal) from [<c0022658>] (do_work_pending+0x94/0xa4)
Mar 22 11:06:52 kernel: [<c0022658>] (do_work_pending) from [<c001f4cc>] (work_pending+0xc/0x20)

 

[mittar]

I have the same errors, RT-AX86U - 386.2 beta3, I disabled AIProtection but the errors remainded:

edit: I found active AIProtection Parental Control so may be it was not disabled as I thought on the end, I am curious if the errors stop.
edit2: I had to use nvram set TM_EULA=0 ... to get the error away, at least I cannot see it anymore

Mar 31 07:54:05 MERLIN kernel: CPU: 1 PID: 7483 Comm: dcd Tainted: P O 4.1.52 #2
Mar 31 07:54:05 MERLIN kernel: Hardware name: Broadcom-v8A (DT)

 

[myStar]

Same here on a AX86U (Firmware-Version: 386.3_beta2)

Jul 22 08:17:07 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 08:17:07 AX86U kernel: CPU: 1 PID: 15702 Comm: dcd Tainted: P O 4.1.52 #2
Jul 22 08:17:07 AX86U kernel: Hardware name: Broadcom-v8A (DT)
Jul 22 08:17:07 AX86U kernel: task: ffffffc025c48bc0 ti: ffffffc03e934000 task.ti: ffffffc03e934000
Jul 22 08:17:07 AX86U kernel: PC is at 0xf747a39c
Jul 22 08:17:07 AX86U kernel: LR is at 0x1dd58
Jul 22 08:17:07 AX86U kernel: pc : [<00000000f747a39c>] lr : [<000000000001dd58>] pstate: 600f0010
Jul 22 08:17:07 AX86U kernel: sp : 00000000ffebbaf8
Jul 22 08:17:07 AX86U kernel: x12: 00000000000a2050
Jul 22 08:17:07 AX86U kernel: x11: 00000000f67ff024 x10: 00000000000a23c4
Jul 22 08:17:07 AX86U kernel: x9 : 00000000f67ff8e4 x8 : 00000000000a287c
Jul 22 08:17:07 AX86U kernel: x7 : 00000000f67ff91c x6 : 00000000000a2876
Jul 22 08:17:07 AX86U kernel: x5 : 0000000000000000 x4 : 00000000f67ff8c8
Jul 22 08:17:07 AX86U kernel: x3 : 0000000000000000 x2 : 00000000ffebbad4
Jul 22 08:17:07 AX86U kernel: x1 : 000000000007d652 x0 : 0000000000000000

and this is not a rare one:

tail -n 1000 /opt/var/log/messages | grep fatal

Jul 22 01:09:32 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 01:36:25 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 02:07:49 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 02:23:39 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 02:47:55 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 02:48:49 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 03:10:07 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 03:19:55 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 03:25:31 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 03:50:02 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 04:13:28 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 04:39:58 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 04:42:48 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 05:05:05 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 05:35:57 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 05:41:16 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 05:51:52 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 05:56:23 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 06:16:51 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 06:19:19 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 06:36:36 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 06:43:43 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 07:12:01 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 07:40:28 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 07:47:09 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 08:12:05 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 08:17:07 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 08:37:16 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 08:57:26 AX86U kernel: potentially unexpected fatal signal 11.
Jul 22 08:59:46 AX86U kernel: potentially unexpected fatal signal 11.

Any Ideas how to fix this? i hope it is not a hardware error?

 

[myStar]

@mittar: any explanation what this is, what this does?

nvram set TM_EULA=0

 

[L&LD]

It revokes the acceptance of the TrendMicro components.

 

[GNUton]

Hi there,
This issue seems to affect also my builds on the DSL-AX82U.
nvram set TM_EULA=0 worked out

 

[mxoz]

Same problem on RT-AX58U / 386.3_2.
"nvram set TM_EUAL=0" didn't help. Getting "potentially unexpected fatal signal 11" every half an hour.

Aug 15 15:05:45 kernel: potentially unexpected fatal signal 11.
Aug 15 15:05:45 kernel: CPU: 1 PID: 1092 Comm: dcd Tainted: P           O    4.1.52 #1
Aug 15 15:05:45 kernel: Hardware name: Generic DT based system
Aug 15 15:05:45 kernel: task: d6cb0000 ti: d0ea0000 task.ti: d0ea0000
Aug 15 15:05:45 kernel: PC is at 0xb6c6b39c
Aug 15 15:05:45 kernel: LR is at 0x1dcd8
Aug 15 15:05:45 kernel: pc : [<b6c6b39c>]    lr : [<0001dcd8>]    psr: 600b0010
Aug 15 15:05:45 kernel: sp : be84f8f8  ip : 000a2050  fp : b60ff024
Aug 15 15:05:45 kernel: r10: 000a23c4  r9 : b60ff7d8  r8 : 000a287c
Aug 15 15:05:45 kernel: r7 : b60ff810  r6 : 000a2876  r5 : 00000000  r4 : b60ff7bc
Aug 15 15:05:45 kernel: r3 : 00000000  r2 : be84f8d4  r1 : 0007d726  r0 : 00000000
Aug 15 15:05:45 kernel: Flags: nZCv  IRQs on  FIQs on  Mode USER_32  ISA ARM  Segment user
Aug 15 15:05:45 kernel: Control: 10c5387d  Table: 1020004a  DAC: 00000015
Aug 15 15:05:45 kernel: CPU: 1 PID: 1092 Comm: dcd Tainted: P           O    4.1.52 #1
Aug 15 15:05:45 kernel: Hardware name: Generic DT based system
Aug 15 15:05:45 kernel: [<c0026fe0>] (unwind_backtrace) from [<c0022c38>] (show_stack+0x10/0x14)
Aug 15 15:05:45 kernel: [<c0022c38>] (show_stack) from [<c044fc54>] (dump_stack+0x8c/0xa0)
Aug 15 15:05:45 kernel: [<c044fc54>] (dump_stack) from [<c003ac4c>] (get_signal+0x490/0x558)
Aug 15 15:05:45 kernel: [<c003ac4c>] (get_signal) from [<c00221d0>] (do_signal+0xc8/0x3ac)
Aug 15 15:05:45 kernel: [<c00221d0>] (do_signal) from [<c0022658>] (do_work_pending+0x94/0xa4)
Aug 15 15:05:45 kernel: [<c0022658>] (do_work_pending) from [<c001f4cc>] (work_pending+0xc/0x20)

Any other ideas what might be wrong or what may fix it?

 

[ColinTaylor]

Same problem on RT-AX58U / 386.3_2.
"nvram set TM_EUAL=0" didn't help. Getting "potentially unexpected fatal signal 11" every half an hour.

Aug 15 15:05:45 kernel: potentially unexpected fatal signal 11.
Aug 15 15:05:45 kernel: CPU: 1 PID: 1092 Comm: dcd Tainted: P           O    4.1.52 #1
Aug 15 15:05:45 kernel: Hardware name: Generic DT based system
Aug 15 15:05:45 kernel: task: d6cb0000 ti: d0ea0000 task.ti: d0ea0000
Aug 15 15:05:45 kernel: PC is at 0xb6c6b39c
Aug 15 15:05:45 kernel: LR is at 0x1dcd8
Aug 15 15:05:45 kernel: pc : [<b6c6b39c>]    lr : [<0001dcd8>]    psr: 600b0010
Aug 15 15:05:45 kernel: sp : be84f8f8  ip : 000a2050  fp : b60ff024
Aug 15 15:05:45 kernel: r10: 000a23c4  r9 : b60ff7d8  r8 : 000a287c
Aug 15 15:05:45 kernel: r7 : b60ff810  r6 : 000a2876  r5 : 00000000  r4 : b60ff7bc
Aug 15 15:05:45 kernel: r3 : 00000000  r2 : be84f8d4  r1 : 0007d726  r0 : 00000000
Aug 15 15:05:45 kernel: Flags: nZCv  IRQs on  FIQs on  Mode USER_32  ISA ARM  Segment user
Aug 15 15:05:45 kernel: Control: 10c5387d  Table: 1020004a  DAC: 00000015
Aug 15 15:05:45 kernel: CPU: 1 PID: 1092 Comm: dcd Tainted: P           O    4.1.52 #1
Aug 15 15:05:45 kernel: Hardware name: Generic DT based system
Aug 15 15:05:45 kernel: [<c0026fe0>] (unwind_backtrace) from [<c0022c38>] (show_stack+0x10/0x14)
Aug 15 15:05:45 kernel: [<c0022c38>] (show_stack) from [<c044fc54>] (dump_stack+0x8c/0xa0)
Aug 15 15:05:45 kernel: [<c044fc54>] (dump_stack) from [<c003ac4c>] (get_signal+0x490/0x558)
Aug 15 15:05:45 kernel: [<c003ac4c>] (get_signal) from [<c00221d0>] (do_signal+0xc8/0x3ac)
Aug 15 15:05:45 kernel: [<c00221d0>] (do_signal) from [<c0022658>] (do_work_pending+0x94/0xa4)
Aug 15 15:05:45 kernel: [<c0022658>] (do_work_pending) from [<c001f4cc>] (work_pending+0xc/0x20)

Any other ideas what might be wrong or what may fix it?

There are hundreds of posts reporting dcd crashes. Try disabling all custom scripts, rebooting the router and seeing if that stops the messages.

 

[mxoz]

There are hundreds of posts reporting dcd crashes. Try disabling all custom scripts, rebooting the router and seeing if that stops the messages.

By custom scripts you mean things like "Diversion", "Skynet", etc? Well, I can try that suggestion just to see if logs disappear, but I need those scripts all the time so not sure how does it help after that..

 

[ColinTaylor]

Yes, custom scripts like Diversion. They can be enabled or disabled en mass in the GUI (Administration > System > Enable JFFS custom scripts and configs).

It helps because it's part of the diagnosis process. If you disable the scripts and the problem persists you have eliminated those as the cause of the problem.

 

[TheMegaMan]

Did anyone actually get to the bottom of this? My RT-AX86U on 388.2_2 firmware is showing the same seg faults in the logs, and I suspect these are related to the random reboots I've been suffering from.

I've done some experimentation, and I'm pretty sure it's not the Trend filter that's affecting mine. With Trend enabled but JFFS scripts disabled, I don't seem to get any of the 'fatal signal 11' errors and register dumps.

However, when I enable the JFFS scripts, I seem to be able to provoke the router into getting more of these, so it seems highly likely it's a script that's causing the issues. I don't have many scripts installed, really just Entware and Diversion (Standard) plus a 2GB Swap File and a start-up Disc Check script.

amtm 3.8 FW by thelonelycoder
RT-AX86U (aarch64) FW-388.2 @ 192.168.1.1
1 open Diversion v4.3.3
ep manage Entware packages no upd
awm Asuswrt-Merlin firmware 388.2.2
_____________________________________________
Everything's up to date (Jul 25 2023 12:52)
_____________________________________________

Are there any known issues with these versions that anyone here is aware of? I have to say, I'm suspecting Diversion, since the error shows itself in the log files when accessing some web pages where I'm sure Diversion is doing it's thing.

It would be a shame not to have Diversion, since the stats show it's blocked quite a few adds already since I did a full router reset last week, but maybe I need to switch to a Pi-hole, instead. Or maybe I've chosen some settings that don't work well.

I'll keep on experimenting, but if anyone has any details to share, it would same me some time!

Thanks,
Adam

 

[ColinTaylor]

Did anyone actually get to the bottom of this?

Yes. dcd is a closed source component of Trend Micro. It has a history of not playing nice with non-Asus code (i.e. addon scripts). There's nothing anyone here can do to make dcd more compatible, and even if there were TrendMicro could update it and compatibility might break again. The most often suspected cause of dcd crashes is pixelserv when used by Diversion.

 

[TheMegaMan]

Ah! So it's an interaction between two different router settings. I don't think I'd ever have worked that out.

So if it's mostly the pixelserv code that's causing the issues, then using Diversion Lite could potentially be more robust. I'm giving that a go, but it seems I've not set it up correctly yet, as it's not reporting having blocked anything yet...and indeed I can still see adverts. On the plus side, I've only seen one register dump so far (about 3 hours ago), and none at all since I subsequently rebooted the router. But then if Diversion Lite isn't actually doing anything, I guess that's not too surprising.

Thanks for the info!

 

[ColinTaylor]

The other sure fire way to stop the dcd crashes is to not use any of the TrendMicro features. Then dcd doesn't run at all.

 

[TheMegaMan]

Well, yes. But then you also lose the protection from malicious web sites that the Trend software performs.

Would you really rather disable that than find an alternative to Diversion (such as Pi-Hole), which merely stops adverts being quite so annoying?

 

[sfx2000]

potentially unexpected fatal signal 11.

sigsev signal 11...

• Dereferencing null pointers - A null pointer is a reserved value that does not point to any object. As a result, the null pointer does not point to any valid memory location. Attempting to access a memory location through a null pointer leads to a SIGSEGV error.
• Buffer overflows - Buffers have a fixed memory size. Writing data that does not fit into a buffer leads to overflowing to adjacent memory locations.
• Invalid permissions - Some memory locations are read-only and reserved for operating system resources. The SIGSEGV error happens when attempting to write data to a read-only memory location leads.
• Freed pointers - If a program references a pointer that is freed, the OS returns a SIGSEGV error.
• Stack overflow - When a program runs out of memory in the call stack and does not have enough allocated memory to run, it leads to a SIGSEGV error.

Everyone says it's TrendMicro, but since one is also running third party scripts...

It could be those scripts and interaction with TrendMicro...