Solved How to read crashlogs?

[toaruScar]

Recently my router crashes frequently. Everytime it generated a crashlog, which includes a section like this:

May  5 13:05:17 crashlog: CPU: 1 PID: 1333 Comm: eapd Tainted: P           O    4.1.52 #2
May  5 13:05:17 crashlog: Hardware name: Generic DT based system
May  5 13:05:17 crashlog: task: d2518800 ti: d26f2000 task.ti: d26f2000
May  5 13:05:17 crashlog: PC is at __skb_recv_datagram+0x37c/0x4e4
May  5 13:05:17 crashlog: LR is at __skb_recv_datagram+0x5c/0x4e4
May  5 13:05:17 crashlog: pc : [<c0323118>]    lr : [<c0322df8>]    psr: 60070093
May  5 13:05:17 crashlog: sp : d26f3de8  ip : 00000000  fp : d26f3e54
May  5 13:05:17 crashlog: r10: d2596074  r9 : 00000000  r8 : d2596080
May  5 13:05:17 crashlog: r7 : d26f2000  r6 : 60070013  r5 : d2596000  r4 : caa84900
May  5 13:05:17 crashlog: r3 : 00000000  r2 : 00000000  r1 : d014f040  r0 : 60070013
May  5 13:05:17 crashlog: Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment user
May  5 13:05:17 crashlog: Control: 10c5387d  Table: 1270004a  DAC: 00000015
May  5 13:05:17 crashlog: Process eapd (pid: 1333, stack limit = 0xd26f2210)
May  5 13:05:17 crashlog: Stack: (0xd26f3de8 to 0xd26f4000)
May  5 13:05:17 crashlog: 3de0:                   d26f3eb4 00000000 00000000 d26f3de8 7fffffff 00000000
May  5 13:05:17 crashlog: 3e00: 0000004e c0214898 00000001 d26f3e48 becc7bd0 00000000 00000000 becc7bd0
May  5 13:05:17 crashlog: 3e20: 00000004 ffffffea 00000000 d2596000 df2dac80 df2dac80 d26f3eac 00000ff0
May  5 13:05:17 crashlog: 3e40: 00000000 c03232b4 d26f3e68 00000000 00000000 00000000 00000000 c04589b4
May  5 13:05:17 crashlog: 3e60: dfbcb9d8 60070113 ffffffea c006de2c 00000000 c007169c c066b580 c065d8c0
May  5 13:05:17 crashlog: 3e80: c04c0710 d26f3f04 c0458964 d6a31280 df2dac80 00000000 00000000 00000000
May  5 13:05:17 crashlog: 3ea0: 0138c420 c03146f8 00000000 00000000 00000000 00000000 00000000 00000ff0
May  5 13:05:17 crashlog: 3ec0: d26f3efc 00000001 00000000 00000000 00000000 d26f3f18 000014a0 d6a31280
May  5 13:05:17 crashlog: 3ee0: 00000000 d26f3f80 00000ff0 c00c47d4 00000ff0 00000000 39e57dcc 0138c420
May  5 13:05:17 crashlog: 3f00: 00000ff0 00000000 00000000 00000ff0 d26f3efc 00000001 d6a31280 00000000
May  5 13:05:17 crashlog: 3f20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 d6a31280
May  5 13:05:17 crashlog: 3f40: 0138c420 d26f3f80 00000000 0138c420 00000ff0 c00c4f30 0000001a becc7bd0
May  5 13:05:17 crashlog: 3f60: 0138d494 d6a31280 d6a31280 00000000 00000000 0138c420 00000ff0 c00c57bc
May  5 13:05:17 crashlog: 3f80: 00000000 00000000 becc7bd0 0138d494 00000005 0138c410 00000003 c001f648
May  5 13:05:17 crashlog: 3fa0: d26f2000 c001f480 0138d494 00000005 0000000f 0138c420 00000ff0 00000000
May  5 13:05:17 crashlog: 3fc0: 0138d494 00000005 0138c410 00000003 00000000 0138d410 00000001 0138c420
May  5 13:05:17 crashlog: 3fe0: 0002b028 becc7b80 00014d14 b6df3290 60070010 0000000f 00000000 00000000
May  5 13:05:17 crashlog: [<c0323118>] (__skb_recv_datagram) from [<c03232b4>] (skb_recv_datagram+0x34/0x3c)
May  5 13:05:17 crashlog: [<c03232b4>] (skb_recv_datagram) from [<c04589b4>] (packet_recvmsg+0x50/0x3a4)
May  5 13:05:17 crashlog: [<c04589b4>] (packet_recvmsg) from [<c03146f8>] (sock_read_iter+0x88/0xb4)
May  5 13:05:17 crashlog: [<c03146f8>] (sock_read_iter) from [<c00c47d4>] (__vfs_read+0xa8/0xd0)
May  5 13:05:17 crashlog: [<c00c47d4>] (__vfs_read) from [<c00c4f30>] (vfs_read+0x7c/0x108)
May  5 13:05:17 crashlog: [<c00c4f30>] (vfs_read) from [<c00c57bc>] (SyS_read+0x3c/0x90)
May  5 13:05:17 crashlog: [<c00c57bc>] (SyS_read) from [<c001f480>] (ret_fast_syscall+0x0/0x3c)
May  5 13:05:17 crashlog: Code: e894000a e5842000 e5842004 e5813004 (e5831000) 
May  5 13:05:17 crashlog: ---[ end trace 723f2a12aa78d9e4 ]---
May  5 13:05:17 crashlog: Kernel panic - not syncing: Fatal exception

The full version can be found here: https://gist.github.com/oscar-c/4c80d95a16c20da2222ff278e9bb94f9
In the log, after the linked moduels section, there's the stack trace (in the code block above). In it, a process called `eapd` is mentioned. Every crashlogs mentions this process in stack trace. Does it mean that this `eapd` has something to do with the frequent crash?

`eapd` probably means a daemon for EAP (Extensible Authentication Protocol), which has something to do with Wi-Fi security?

 

[toaruScar]

So it turned out that my guess is right.
The `eapd` caused crashes everyday becaused I enabled WPA2/WPA3 mixed mode.
After I changed the setting to "WPA2 only", there hasn't been any crash in the past week.

 

[Justinh]

Good job. Did you report to ASUS?

 

[toaruScar]

Did you report to ASUS?

I tought posting my discovery here is reporting, becasue ASUS router devs visit snb.

 

[ColinTaylor]

I thought posting my discovery here is reporting,

No it isn't.

because ASUS router devs visit snb.

Very rarely, and only when they have a particular reason. They will ignore all posts like this.