http://bugs.winehq.org/show_bug.cgi?id=12548
Summary: New default for /proc/sys/vm/mmap_min_addr clashing with wine preloader Product: Wine Version: CVS/GIT Platform: Other URL: https://launchpad.net/bugs/114025 OS/Version: other Status: NEW Severity: normal Priority: P2 Component: loader AssignedTo: wine-bugs@winehq.org ReportedBy: dank@kegel.com
The problem http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-0600 prompted distributions to raise the default for /proc/sys/vm/mmap_min_addr or even DEFAULT_MMAP_MIN_ADDR to 64K from 0. This causes the following error message when starting (some?) wine apps: Problem with wine preloader: Warning: failed to reserve range 00000000-60000000 See discussion: https://launchpad.net/bugs/114025 http://kerneltrap.org/Linux/Patching_CVE-2008-0600_Local_Root_Exploit http://kerneltrap.org/Linux/2.4.36_Stable_Release
You can check to see if you're on an affected system by doing "cat /proc/sys/vm/mmap_min". If that succeeds, and its value is nonzero, you're probably running into this.
To work around the problem temporarily, you can change this value with the command sudo sysctl -w vm.mmap_min_addr=0 but that value gets reset at boot. To work around the problem more persistantly, also edit the file /etc/sysctl.conf like this:
# protect bottom 64k of memory from mmap to prevent NULL-dereference # attacks against potential future kernel security vulnerabilities. # (Added in kernel 2.6.23.) -vm.mmap_min_addr = 65536 +vm.mmap_min_addr = 0
http://kerneltrap.org/Linux/2.4.36_Stable_Release suggests using a value of 4096 for this. "Advanced Windows", 3rd edition, says that the memory area 0 to 4095 is not mapped anyway in windows (it's a guard page). So maybe when Wine is installed, we could somehow change that value to 4096, and have Wine's preloader happily continue if it can't map the bottom page of RAM.