Re: kern/50664: "cd .." over NFS/ZFS can panic kernel

["J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>]

The following reply was made to PR kern/50664; it has been noted by GNATS.

From: "J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>
To: Brian Marcotte <marcotte%panix.com@localhost>
Cc: gnats-bugs%NetBSD.org@localhost
Subject: Re: kern/50664: "cd .." over NFS/ZFS can panic kernel
Date: Sun, 17 Jan 2016 15:33:13 +0100

 Fine.
 
 We have =E2=80=9C/net/u=E2=80=9D as 0xc1b39dd0, =E2=80=9C.zfs=E2=80=9D =
 as 0xc1b39bc0 and =E2=80=9Cshares=E2=80=9D as 0xc1b39a60.
 
 Now we enter (0xc1b39a60 0xc1b39a60 "..=E2=80=9D), this enters =
 "shares=E2=80=9D as its own parent.
 
 Could you add a panic() after the printf so we get the backtrace when =
 things go wrong:
 
 +printf("enter %p %p \"%.*s\"\n", dvp, vp, cnp->cn_namelen, =
 cnp->cn_nameptr);
 +if (dvp =3D=3D vp && cnp->cn_namelen =3D=3D 2 && =
 strncmp(cnp->cn_nameptr, =E2=80=9C..=E2=80=9D, 2) =3D=3D 0)
 +	panic(=E2=80=9Cbad parent=E2=80=9D);
 
 --
 J. Hannken-Illjes - hannken%eis.cs.tu-bs.de@localhost - TU Braunschweig (Germany)=