>Number:         29898
>Category:       kern
>Synopsis:       mount(2) can corrupt filesystem
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Apr 06 04:30:00 +0000 2005
>Originator:     YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
>Release:        NetBSD 3.99.3
>Organization:

>Environment:
	
	
System: NetBSD kaeru 3.99.3 NetBSD 3.99.3 (build.kaeru.nodebug) #35: Tue Apr 5 15:52:06 JST 2005 takashi@kaeru:/home/takashi/work/kernel/build.kaeru.nodebug i386
Architecture: i386
Machine: i386
>Description:
	as mount(2) temporarily alters important mnt_flag like MNT_SOFTDEP,
	if there're other activities on the filesystem in the mean time,
	you'll lose.  in the worst case, it ends up corrupting the filesystem.
	mount(2) with MNT_GETARGS is esp. harmful because it can be done
	by arbitrary users.
>How-To-Repeat:
	code inspection.
>Fix:
	restructure mount related code so that the caller of
	VFS_MOUNT doesn't need to alter mnt_flag/iflag.
	maybe by adding more arguments to VFS_MOUNT to describe the operation.

>Unformatted: