COMMAND
tmpfs(4)
SYSTEMS AFFECTED
SunOS 4.1.x
PROBLEM
Unprivileged users can panic the SunOS 4.1.x kernel if the TMPFS
filesystem is in use.
Assuming /tmp is a tmpfs filesystem:
% cd /tmp
% /usr/etc/mknod fifo p
% ln fifo link
% ls -ClFg link fifo
The problem actually occurs with any 'special' file on the
tmpfs filesystem. tmp_link() incorrectly updates the link count
(va_nlink in struct vattr) in the snode's vnode rather than in
the real vnode.
SOLUTION
This bug can be fixed by the patch 100507-06 (which is for
SunOS4.1.3, but apply to SunOS4.1.4 anyway).