kern/55614: kernel diagnostic assertion "solocked(sb->sb_so)" failed

[martin%NetBSD.org@localhost]

>Number:         55614
>Category:       kern
>Synopsis:       kernel diagnostic assertion "solocked(sb->sb_so)" failed
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Aug 29 11:45:00 +0000 2020
>Originator:     Martin Husemann
>Release:        NetBSD 9.99.72
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD gethsemane.duskware.de 9.99.72 NetBSD 9.99.72 (GETHSEMANE) #76: Sat Aug 29 12:15:02 CEST 2020 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/macppc/compile/GETHSEMANE macppc
Architecture: powerpc
Machine: macppc
>Description:

While trying to scp new binary sets to this machine, I get a (mostly 
reproducable) KASSERT failure:

[ 155.5779572] panic: kernel diagnostic assertion "solocked(sb->sb_so)" failed: file "../../../../sys/socketvar.h", line 407 
[ 155.6079637] cpu1: Begin traceback...
[ 155.6179685] 0x10593c40: at vpanic+0x12c
[ 155.6279737] 0x10593c70: at kern_assert+0x60
[ 155.6379786] 0x10593cb0: at tcp_output+0x1a88
[ 155.6479840] 0x10593d80: at tcp_rcvd_wrapper+0xc8
[ 155.6579888] 0x10593db0: at soreceive+0x4a8
[ 155.6679954] 0x10593e60: at dofileread+0x88
[ 155.6779981] 0x10593eb0: at syscall+0x2fc
[ 155.6880039] 0x10593f20: user SC trap #3 by 0xfd1c0e18: srr1=0xd032
[ 155.6980085]             r1=0xffffa460 cr=0x48008242 xer=0 ctr=0xfd1c0e10
[ 155.7080134] cpu1: End traceback...
[ 155.7180182] halting CPU 0
[ 155.7180182] dumpsys: TBD
[ 155.7180182] rebooting


>How-To-Repeat:

s/a

>Fix:
n/a