panic: map ADDR end = ADDR, next->start = 0

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 4ed8c797 Fix Q_TOSTR(3) with GCC when it's called with fir..
git tree: freebsd
console output: https://syzkaller.appspot.com/x/log.txt?x=1451335b600000
dashboard link: https://syzkaller.appspot.com/bug?extid=8b9625ac264972940dee
userspace arch: i386

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+8b9625...@syzkaller.appspotmail.com

panic: map 0xfffff80012cb9000 end = 28401000, next->start = 0
cpuid = 1
time = 1569704935
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame
0xfffffe00244ae190
vpanic() at vpanic+0x1e0/frame 0xfffffe00244ae1f0
panic() at panic+0x43/frame 0xfffffe00244ae250
_vm_map_assert_consistent() at _vm_map_assert_consistent+0x226/frame
0xfffffe00244ae2b0
vm_map_lookup_entry() at vm_map_lookup_entry+0x374/frame 0xfffffe00244ae330
vm_map_lookup() at vm_map_lookup+0x13e/frame 0xfffffe00244ae430
vm_fault() at vm_fault+0x7b/frame 0xfffffe00244ae5c0
vm_fault_trap() at vm_fault_trap+0xd7/frame 0xfffffe00244ae620
trap_pfault() at trap_pfault+0x404/frame 0xfffffe00244ae6a0
trap() at trap+0x44f/frame 0xfffffe00244ae7c0
calltrap() at calltrap+0x8/frame 0xfffffe00244ae7c0
--- trap 0xc, rip = 0xffffffff818877b7, rsp = 0xfffffe00244ae890, rbp =
0xfffffe00244ae890 ---
copyin_nosmap_erms() at copyin_nosmap_erms+0x187/frame 0xfffffe00244ae890
freebsd32_sendmsg() at freebsd32_sendmsg+0x4bf/frame 0xfffffe00244ae970
ia32_syscall() at ia32_syscall+0x46a/frame 0xfffffe00244aeab0
int0x80_syscall_common() at int0x80_syscall_common+0x9c/frame 0x8142fef
KDB: enter: panic
[ thread pid 4344 tid 100533 ]
Stopped at kdb_enter+0x6a: movq $0,kdb_why


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.