Re: CURRENT: kernel panic in IPFW while stopping jails

On 2025-12-26 17:32, A FreeBSD User wrote:
> Am Tage des Herren Thu, 25 Dec 2025 19:08:36 +0100
> FreeBSD User <freebsd@walstatt-de.de> schrieb:
> 
>> On Thu, 25 Dec 2025 18:30:45 +0100 (CET)
>> Ronald Klop <ronald-lists@klop.ws> wrote:
>> 
>> > Do you use bpf or tap in your ipfw rules?
>> > A panic with that was mentioned on the 20th. And fixed in the mean time of I
>> > remember correctly. https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=291854
>> > Regards,Ronald  
>> 
>> Indeed, all boxes in question do have a tap0 at least defined -but in only one
>> case used.
>> 
>> Kind regards,
>> 
>> oh
>> 
>> 
>> > 
>> > Van: FreeBSD User <freebsd@walstatt-de.de>
>> > Datum: 25 december 2025 17:09
>> > Aan: FreeBSD CURRENT <freebsd-current@freebsd.org>
>> > Onderwerp: CURRENT: kernel panic in IPFW while stopping jails
>> >   
>> > > 
>> > > 
>> > > Hello,
>> > > 
>> > > on recent CURRENT ipfw (in my case compiled into kernel) either restarting
>> > > "ipfw" via "service ipfw restart" or restarting jails using also ipfw on a
>> > > host also using ipfw (jail-hoster also ipfw compiled into kernel) causes a
>> > > fatal kernel crash.
>> > > 
>> > > This issue is present since last week an wreak havok to several boxes with
>> > > OS installed on UFS/FFS SSDs. In one case I have only pictures/screenshots
>> > > made via smartphone - while crashing, kernel debugger input pops up on
>> > > console, but I'm able to typein something within the first seconds and this
>> > > is mostly "reboot" but gets stuck with "re" in most cases. "bt" freezes
>> > > system immediately.
>> > > 
>> > > At least I can reproduce this misbehaviour on all recent CURRENT were IPFW
>> > > is compiled into kernel. Anybody else havong this trouble?
>> > > 
>> > > Kind regards,
>> > > 
>> > > Oliver
>> > > 
>> > > Merry Christmas to everyone.
>> > > 
>> > > -- 
>> > > 
>> > > A FreeBSD user
>> > > 
>> > > 
>> > > 
>> > > 
>> > >     
>> 
>> 
> 
> tap0 disabled/deleted. Same issue on every box.

$ git bisect log
git bisect start
# status: waiting for both good and bad commits
# bad: [086bedb11a853801e82234b8a1a64f0df52d9e52] tools.build: also add
sys/_visible.h to SYSINCS
git bisect bad 086bedb11a853801e82234b8a1a64f0df52d9e52
# status: waiting for good commit(s), bad commit known
# good: [44cb1e857f048d2326bdc1a032ccd2c04d2bcdc9] tcp: improve
credential handling in syncache
git bisect good 44cb1e857f048d2326bdc1a032ccd2c04d2bcdc9
# good: [b0c7eaf83d21bbc333e247ab9e136965b3ca54ed] bhyve/slirp: Drop
privileges before entering capability mode
git bisect good b0c7eaf83d21bbc333e247ab9e136965b3ca54ed
# good: [6a75e3951506c12b42428a47710d07cadcdd723e] ofed/libibverbs:
remove strdupa() hack from config.h
git bisect good 6a75e3951506c12b42428a47710d07cadcdd723e
# bad: [1fad49baf390cb52f238e6c352d0bc0893c008c3] sdhci: Try to complete
the last transaction if dumping
git bisect bad 1fad49baf390cb52f238e6c352d0bc0893c008c3
# good: [9d9974457ce8c6cf9023884ab457d4712dcc237f] bhyvectl: fix build
without BHYVE_SNAPSHOT
git bisect good 9d9974457ce8c6cf9023884ab457d4712dcc237f
# bad: [52395203f9ac40d321ed55d93e9887300261d3bf] MFV: Import blocklist
2025-12-15 (8a4b011)
git bisect bad 52395203f9ac40d321ed55d93e9887300261d3bf
# good: [c112ad75605ccdfcb8bbce2f57b0e7a077f057f8] options: describe
WITH_IPFILTER_IPFS
git bisect good c112ad75605ccdfcb8bbce2f57b0e7a077f057f8
# good: [8774a990ee4094f16d596d4b78e0f3239e5d0c88] bpf: modularize
ifnet(9) part of bpf
git bisect good 8774a990ee4094f16d596d4b78e0f3239e5d0c88
# bad: [1615eff94cda8619561b73186ec8098cc8b14c5c] usb: don't create
ifnet(9) for usbus devices
git bisect bad 1615eff94cda8619561b73186ec8098cc8b14c5c
# good: [ddf4f9eda9c295082f17e7f26963666b72c97bb9] ipfw: create "ipfw0"
and "ipfwlog0" bpf tapping points without ifnet(9)
git bisect good ddf4f9eda9c295082f17e7f26963666b72c97bb9
# bad: [3daae1ac1d82ecdcd855101bab5206e914b12350] ipfw: create a bpf tap
point for every log rule
git bisect bad 3daae1ac1d82ecdcd855101bab5206e914b12350
# good: [1c5021f5251b231b614ad9cd175bcb4250495c12] ifconfig: print
warning and return success on ipfw0, ipfwlog0 cloning
git bisect good 1c5021f5251b231b614ad9cd175bcb4250495c12
# first bad commit: [3daae1ac1d82ecdcd855101bab5206e914b12350] ipfw:
create a bpf tap point for every log rule

https://codeberg.org/FreeBSD/freebsd-src/commit/3daae1ac1d82ecdcd855101bab5206e914b12350
ipfw: create a bpf tap point for every log rule

Dynamically allocate bpf tap points for every rule that has "log".
The name is "ipfw%u", where %u is substituted to the rule number.
The default catch all "ipfw0" tap still exists for compatibility
and it will catch packets in case if there are no bpf listeners
on a per-rule tap.

Reviewed by:		ae
Differential Revision:	https://reviews.freebsd.org/D53877