panic: udp_output: shared udbinfo lock, excl inp lock (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 219791b2 Follow the FreeBSD and implement PDEATH_SIG prctl..
git tree: freebsd
console output: https://syzkaller.appspot.com/x/log.txt?x=15d99742a00000
dashboard link: https://syzkaller.appspot.com/bug?extid=bdf4caa36f3ceeac198f

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+bdf4ca...@syzkaller.appspotmail.com

panic: udp_output: shared udbinfo lock, excl inp lock
cpuid = 0
time = 3
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame
0xfffffe0024b80550
vpanic() at vpanic+0x1e0/frame 0xfffffe0024b805b0
panic() at panic+0x43/frame 0xfffffe0024b80610
udp_send() at udp_send+0x139c/frame 0xfffffe0024b80730
sosend_dgram() at sosend_dgram+0x550/frame 0xfffffe0024b807a0
sosend() at sosend+0xc6/frame 0xfffffe0024b80810
kern_sendit() at kern_sendit+0x35e/frame 0xfffffe0024b808c0
sendit() at sendit+0x226/frame 0xfffffe0024b80920
sys_sendmsg() at sys_sendmsg+0x8b/frame 0xfffffe0024b80980
amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe0024b80ab0
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe0024b80ab0
--- syscall (198, FreeBSD ELF64, nosys), rip = 0x412fda, rsp =
0x7fffdffbbf38, rbp = 0x3 ---
KDB: enter: panic
[ thread pid 1558 tid 101235 ]
Stopped at kdb_enter+0x6a: movq $0,kdb_why


---
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 219791b2 Follow the FreeBSD and implement PDEATH_SIG prctl..
git tree: freebsd

console output: https://syzkaller.appspot.com/x/log.txt?x=1463fdcca00000
dashboard link: https://syzkaller.appspot.com/bug?extid=bdf4caa36f3ceeac198f
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16d20134a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+bdf4ca...@syzkaller.appspotmail.com

login: panic: udp_output: shared udbinfo lock, excl inp lock
cpuid = 1
time = 1556678010

KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame

0xfffffe00212b1550
vpanic() at vpanic+0x1e0/frame 0xfffffe00212b15b0
panic() at panic+0x43/frame 0xfffffe00212b1610
udp_send() at udp_send+0x139c/frame 0xfffffe00212b1730
sosend_dgram() at sosend_dgram+0x550/frame 0xfffffe00212b17a0
sosend() at sosend+0xc6/frame 0xfffffe00212b1810
kern_sendit() at kern_sendit+0x35e/frame 0xfffffe00212b18c0
sendit() at sendit+0x226/frame 0xfffffe00212b1920
sys_sendmsg() at sys_sendmsg+0x8b/frame 0xfffffe00212b1980
amd64_syscall() at amd64_syscall+0x436/frame 0xfffffe00212b1ab0
fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe00212b1ab0

--- syscall (198, FreeBSD ELF64, nosys), rip = 0x412fda, rsp =
0x7fffdffbbf38, rbp = 0x3 ---
KDB: enter: panic

[ thread pid 935 tid 100312 ]