Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Connecting to a remote machine of different endianness architecture using the X Display Manager Control Protocol (XDMCP) could cause unexpected termination of the X server when the data length in the XkbSetGeometry request was erroneously swapped twice, and an incorrect value was produced. With this update, the data is swapped only once when appropriate, ensuring the use of correct data length. Connecting to remote machines no longer causes X server crashes in this situation.
DescriptionMichal Domonkos
2013-09-11 17:32:00 UTC
Created attachment 796457[details]
backtrace
Description of problem:
Connecting through XDMCP to a remote machine sometimes ends up in a crash with the following backtrace in the terminal (refer to the attachment for a backtrace from gdb). I've managed to reproduce this only on ppc64 arch but it may not be arch-specific.
(EE)
(EE) Backtrace:
(EE) 0: Xephyr (xorg_backtrace+0x36) [0x464fb6]
(EE) 1: Xephyr (0x400000+0x6ad19) [0x46ad19]
(EE) 2: /lib64/libpthread.so.0 (0x3e1d800000+0xf500) [0x3e1d80f500]
(EE) 3: /lib64/libc.so.6 (memcpy+0x2eb) [0x3e1d489b0b]
(EE) 4: Xephyr (0x400000+0x16de52) [0x56de52]
(EE) 5: Xephyr (0x400000+0x17689d) [0x57689d]
(EE) 6: Xephyr (0x400000+0x1772a5) [0x5772a5]
(EE) 7: Xephyr (0x400000+0x30059) [0x430059]
(EE) 8: Xephyr (0x400000+0x9397a) [0x49397a]
(EE) 9: /lib64/libc.so.6 (__libc_start_main+0xfd) [0x3e1d41ecdd]
(EE) 10: Xephyr (0x400000+0x1dba9) [0x41dba9]
(EE)
(EE) Segmentation fault at address 0x1133000
Fatal server error:
Caught signal 11 (Segmentation fault). Server aborting
Version-Release number of selected component (if applicable):
xorg-x11-server-Xephyr-1.13.0-11.el6.x86_64
How reproducible:
random
Steps to Reproduce:
1. Put Enable=true under [xdmcp] section in /etc/gdm/custom.conf on the host
2. Restart GDM on the host (initctl restart prefdm)
3. Disable firewall on both the host and client machine
4. Connect from the client using: Xephyr :99 -query <host-ip>
Actual results:
At some point, before a remote GDM instance has finished loading, Xephyr crashes.
Expected results:
No crash.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://rhn.redhat.com/errata/RHBA-2015-1445.html
Created attachment 796457 [details] backtrace Description of problem: Connecting through XDMCP to a remote machine sometimes ends up in a crash with the following backtrace in the terminal (refer to the attachment for a backtrace from gdb). I've managed to reproduce this only on ppc64 arch but it may not be arch-specific. (EE) (EE) Backtrace: (EE) 0: Xephyr (xorg_backtrace+0x36) [0x464fb6] (EE) 1: Xephyr (0x400000+0x6ad19) [0x46ad19] (EE) 2: /lib64/libpthread.so.0 (0x3e1d800000+0xf500) [0x3e1d80f500] (EE) 3: /lib64/libc.so.6 (memcpy+0x2eb) [0x3e1d489b0b] (EE) 4: Xephyr (0x400000+0x16de52) [0x56de52] (EE) 5: Xephyr (0x400000+0x17689d) [0x57689d] (EE) 6: Xephyr (0x400000+0x1772a5) [0x5772a5] (EE) 7: Xephyr (0x400000+0x30059) [0x430059] (EE) 8: Xephyr (0x400000+0x9397a) [0x49397a] (EE) 9: /lib64/libc.so.6 (__libc_start_main+0xfd) [0x3e1d41ecdd] (EE) 10: Xephyr (0x400000+0x1dba9) [0x41dba9] (EE) (EE) Segmentation fault at address 0x1133000 Fatal server error: Caught signal 11 (Segmentation fault). Server aborting Version-Release number of selected component (if applicable): xorg-x11-server-Xephyr-1.13.0-11.el6.x86_64 How reproducible: random Steps to Reproduce: 1. Put Enable=true under [xdmcp] section in /etc/gdm/custom.conf on the host 2. Restart GDM on the host (initctl restart prefdm) 3. Disable firewall on both the host and client machine 4. Connect from the client using: Xephyr :99 -query <host-ip> Actual results: At some point, before a remote GDM instance has finished loading, Xephyr crashes. Expected results: No crash.