amd64/186645: Crash after unmounting wdfs

[Sebastian Chmielewski]

>Number:         186645
>Category:       amd64
>Synopsis:       Crash after unmounting wdfs
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-amd64
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Feb 11 09:20:00 UTC 2014
>Closed-Date:
>Last-Modified:
>Originator:     Sebastian Chmielewski
>Release:        9.2-RELEASE
>Organization:
>Environment:
FreeBSD xxxxx 9.2-RELEASE-p3 FreeBSD 9.2-RELEASE-p3 #0: Sat Jan 11 03:25:02 UTC 2014     root at amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC amd64 amd64 Intel(R) Core(TM) i7-3740QM CPU @ 2.70GHz FreeBSD

>Description:
FreeBSD crashes and reboots after unmounting wdfs (WebDav) resource
>How-To-Repeat:
- pkg install fuse_wdfs
- wdfs https://confluence.xxxx/plugins/servlet/confluence/default/Global/SOMEPROJECT Wiki
- navigate in Wiki
- exit from Wiki directory
- umount Wiki
- crash

stacktrace from core.txt.0

Fatal trap 1: privileged instruction fault while in kernel mode
cpuid = 1; apic id = 01
instruction pointer     = 0x20:0xffffffff82c67543
stack pointer           = 0x28:0xffffff848fb0e4c0
frame pointer           = 0x28:0xffffff848fb0e500
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 4365 (umount)
trap number             = 1
panic: privileged instruction fault
cpuid = 1
KDB: stack backtrace:
#0 0xffffffff80947986 at kdb_backtrace+0x66
#1 0xffffffff8090d9ae at panic+0x1ce
#2 0xffffffff80cf2110 at trap_fatal+0x290
#3 0xffffffff80cf2921 at trap+0x241
#4 0xffffffff80cdbd53 at calltrap+0x8
#5 0xffffffff80b93c5e at vnode_pager_dealloc+0xae
#6 0xffffffff80b85c59 at vm_object_terminate+0x1a9
#7 0xffffffff80b92ce9 at vnode_destroy_vobject+0xb9
#8 0xffffffff82c618a1 at fuse_reclaim+0x21
#9 0xffffffff80d98c78 at VOP_RECLAIM_APV+0x78
#10 0xffffffff809aa264 at vgonel+0x134
#11 0xffffffff809ad76e at vflush+0x2de
#12 0xffffffff82c6023b at fuse_unmount+0x1db
#13 0xffffffff809a2056 at dounmount+0x3d6
#14 0xffffffff809a28c8 at sys_unmount+0x4a8
#15 0xffffffff80cf18ba at amd64_syscall+0x5ea
#16 0xffffffff80cdc037 at Xfast_syscall+0xf7
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: