Re: kern/52728: "mount -u /dev/ /" triggers kernel panic

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR kern/52728; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/52728: "mount -u /dev/ /" triggers kernel panic
Date: Wed, 15 Nov 2017 18:22:43 +0000

 On Wed, Nov 15, 2017 at 01:50:01PM +0000, Izumi Tsutsui wrote:
  > >Number:         52728
  > - boot NetBSD/i386 (or maybe any port) to single user
  > - type "mount -u /dev/ /" on root shell
 
 oy :-/
 
  > Stopped in pid 11.1 (mount_ffs) at     netbsd:ffs_mount+0xa1:  movl    c(%edx),%ecx
  > db{0}> bt
  > ffs_mount(c2f03008,bfb1eb9c,c2a0a198,db4eef30,c2f03008,db4eef0c,c0991343,c2f0300
  > 8,bfb1eb9c,c2a0a198) at netbsd:ffs_mount+0xa1
 
 If someone has time to wade into it, figuring out where in ffs_mount
 this is would be helpful. There's no obvious issue, and with -u the
 passed-in device should mostly be ignored.
 
 (Also, it looks like doing this might, if it doesn't crash first,
 reach the call to set_statvfs_info near the bottom with a wrong path,
 which is probably not desirable; but that doesn't seem to be the
 crash.)
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost