[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] Bug#636035: qemu-user: init_paths() doesnt guard against re
From: |
Johannes Schauer |
Subject: |
[Qemu-devel] Bug#636035: qemu-user: init_paths() doesnt guard against recursive link cycles |
Date: |
Sat, 30 Jul 2011 14:24:34 +0200 |
Package: qemu-user
Version: 0.14.1+dfsg-3
Severity: normal
Hi,
when a symbolic or hardlink which creates a recursive cycle exists in
the directory specified as the elf interpreter prefix
(default=/etc/qemu-binfmt/<arch>/), qemu-user will recursively traverse
this path and never finish (eating tons of memory in the process).
The easiest way to reproduce is to do:
ln -s '.' /etc/qemu-binfmt/<arch>/foobar
(or wherever directory you pointed qemu to with the -L option)
This is mostly annoying because there exists the /usr/bin/X11 symlink
which points to '.' in debian systems with x11-common installed.
Other problems occur with /proc/self/fd/ (and /dev/fd/ which links to
it) when /proc is mounted in the elf interpreter prefix path.
The problem occurs when init_paths() is called on interp_prefix (the elf
interpreter prefix path). init_paths() doesnt protect from infinitely
traversing cyclic symlinks.
find(1) solves this problem by maintaining a hashtable of (to be)
traversed directories and skipping directories that are found to be
already part of it.
I can prepare a patch for path.c (which defines init_paths()) which
guards against this behaviour in the same way that find(1) does if this
problem is desired to be solved that way.
cheers, josch
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- [Qemu-devel] Bug#636035: qemu-user: init_paths() doesnt guard against recursive link cycles,
Johannes Schauer <=