Date: Thu, 18 Jul 1996 15:22:36 -0700 (PDT) From: Paul Traina <pst@jnx.com> To: FreeBSD-gnats-submit@freebsd.org Subject: kern/1399: vnode-pager Message-ID: <199607182222.PAA14261@red.jnx.com> Resent-Message-ID: <199607182340.QAA28830@freefall.freebsd.org>
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>Number: 1399 >Category: kern >Synopsis: invoking setuid programs over NFS case vnode_pager error msgs >Confidential: no >Severity: non-critical >Priority: medium >Responsible: freebsd-bugs >State: open >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Thu Jul 18 16:40:02 PDT 1996 >Last-Modified: >Originator: Paul Traina >Organization: Juniper Networks, Inc. >Release: FreeBSD 2.2-CURRENT i386 >Environment: FreeBSD 2.2-CURRENT FreeBSD 2.2-CURRENT #0: Wed Jul 17 18:28:54 PDT 1996 >Description: vnode_pager_getpages: I/O read error vm_fault: pager input (probably hardware) error, PID 12278 failure pid 12278 (R), uid 0: exited on signal 11 Is generated when I attempt to execute a setuid root program over NFS where the setuid program can no longer read itself once it has begun to operate. >How-To-Repeat: I created the following program: -r-sr-x--- 1 root pst 13039 Jul 17 14:05 bin/i386/foobar Once the program begins to execute, it is no longer readable by the new effective UID because this program is being read in over NFS and the standard root privilege mapping prohibits reading. Changing the permissions on the program to -r-sr-xr-x 1 root pst 13039 Jul 17 14:05 bin/i386/foobar solves the problem, but clearly the error message is incorrect, and in fact we should handle this situation a tad more gracefully. I don't have the slightest idea how to change the vnode pager, but it probably should continue to operate under the original uid of the invoker (ugh, what would that change break elsewhere?) as a conservative measure since the invoker could never have started the program otherwise. >Fix: >Audit-Trail: >Unformatted:
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