[Bug 216398] Re: dosemu segfaults on startup
Change was in 2.6.23 kernel update, lines 18-21 of /etc/sysctl.conf. Suggested vm.mmap_min_addr be changed back to zero for Intrepid, as functionality for non-technical users should be more important the protecting the lower 64kb of memory. The linux kernel has a good track record for security vulnerabilities and vulnerabilities exploiting a dereferenced NULL pointer are rare. This also affects hardware virtualisation. This was discussed in the LKML (https://kerneltrap.org/mailarchive /linux-kernel/2007/6/5/100078) and it was decided that min_addr=0 should be the default behavior so as not to break user-land by default. Excerpt from /etc/sysctl.conf below: # 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 Suggested change to: # If enabled (set to 65536) will prevent userland from allocating # more memory, which is more secure. However some features will # break including dosemu, wine and hardware virtualisation. vm.mmap_min_addr = 0 Finally I request this bug be moved to the ubuntu kernel, as it affects not only dosemu, but also wine, hardware virtualisation and an unknown number of other userland programs. ** Attachment added: mmap_min_addr.patch http://launchpadlibrarian.net/18801004/mmap_min_addr.patch -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
** Changed in: procps (Ubuntu) Sourcepackagename: dosemu = procps -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
@Stephan Wijering wrote on 2008-04-25: I solved this problem, i was running the program on a samba server and the old method of smbfs doesnt work anymore, i needed to mount using cifs, but it was nessecary tot add the line unix extensions = no in the global section of the smb.conf on the server. Everyting works reasonbly well now. -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
I can confirm this bug and it's workaround on Hardy. -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
not like it's needed, but I confirm as well. I mostly use dosemu to run populous 2, which works fine for me once I set mmap_min_addr to 0. -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
i confirm this bug as well as the workaround setting sudo sysctl -w vm.mmap_min_addr=0. this seems to be related to https://bugs.launchpad.net/ubuntu/+source/wine/+bug/114025/ . ** Changed in: dosemu (Ubuntu) Status: New = Confirmed -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
Have anyone found a permanent solution yet? echo 0 | sudo tee /proc/sys/vm/mmap_min_addr must be rewrote after each restart of the computer. -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
Permanent fix: with root privileges edit /etc/sysctl.conf file; find the line that reads vm.mmap_min_addr = 65536 and change the number from 65536 to 0 (zero). Save and restart. -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
Permanent fix: with root privleges edit /etc/sysctl.conf file; find the line that reads vm.mmap_min_addr = 65536 and change the number from 65536 to 0 (zero). Save and restart. -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
Re: [Bug 216398] Re: dosemu segfaults on startup
On Sun, 2008-04-27 at 13:50 +, Nagy Tamás wrote: Have anyone found a permanent solution yet? echo 0 | sudo tee /proc/sys/vm/mmap_min_addr must be rewrote after each restart of the computer. Manipulations of /proc/sys can be done through sysctl and can be made to be automatically applied at every boot by editing /etc/sysctl.conf In this case, the following command performs the same as the above: $ sudo sysctl vm.mmap_min_addr=0 So adding the line: vm.mmap_min_addr=0 to /etc/sysctl.conf will make that change automatically with each boot. I have not tested running the system with this change so I do not know if making it the default on your system will cause some other unintended consequences. Hmm... actually, I looked at my sysctl.conf file and found 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 So it seems that the current value was set this way on purpose, for security reasons. This probably should be investigated further. -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
Re: [Bug 216398] Re: dosemu segfaults on startup
Thanks Edward. Did this and now Dosemu boots OK. However when I try to run an exe program it say that it can't access the temp directory. Again works OK if I launch using sudo. Regards, John Catt. Edward Mendelson wrote: Permanent fix: with root privleges edit /etc/sysctl.conf file; find the line that reads vm.mmap_min_addr = 65536 and change the number from 65536 to 0 (zero). Save and restart. -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
anyone have problems with keyboard layout too ? only under root see the right layout. may be related ? Thanks -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
I can confirm this bug, and also that the suggested fix permits dosemu to work again. dosemu has worked on Hardy for me since i originally installed it at beta5. However, it quit working when the kernel update to kernel 2.6.24-16-generic occurred. I really need to have dosemu working properly before putting Hardy on my production system. It is a good thing I found the problem before upgrading that system. Please release a supported fix for this problem. George -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
Dosemu does start after aplying the workaround but my dos program doesnt, it worked in 7.10 -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
same here The fix suggested doesn't work on Kubuntu 8.04 [EMAIL PROTECTED]:~$ sudo echo 0 /proc/sys/vm/mmap_min_addr bash: /proc/sys/vm/mmap_min_addr: Permesso negato -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
need to learn to use sudo. echo 0 | sudo tee /proc/sys/vm/mmap_min_addr -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
shame on me ;-( -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
Also here. The fix suggested above works. dosemu.bin[4032]: segfault at 000f eip b7e019b5 esp bfb4908c error 6 $ cat /proc/version_signature Ubuntu 2.6.24-16.30-generic $ uname -a Linux my_hostname 2.6.24-16-generic #1 SMP Thu Apr 10 13:23:42 UTC 2008 i686 GNU/Linux -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 216398] Re: dosemu segfaults on startup
A (temporary ?) workaround is to be found at http://marc.info/?l=linux- msdosm=120802271919730w=2 -- dosemu segfaults on startup https://bugs.launchpad.net/bugs/216398 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
