Re: qemu-kvm-1.2.0: double free or corruption in VNC code
Hello Stefan, thanks for Your time looking at it. Thanks, I looked at the backtrace in the source tree. Unfortunately the root cause is not obvious to me. I was looking for a double-free of the zrle buffers. If this bug repeatedly bites you, try a different VNC encoding as a workaround (not ZRLE). Well, when I reported the problem, it was first time it appeared, so I didn't consider it big deal, but yesterday we got it again, on different server (but the backtrace is completely the same) But it was the same person as before (and quite a new user to our KVM guests), so I suspect it can be something specific to his client or setup. I'll try to look at it deeper and let You know if I figure something out... cheers nik Perhaps someone more familiar with the VNC code will be able to see it. All the information you have provided is helpful. Stefan -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- - Ing. Nikola CIPRICH LinuxBox.cz, s.r.o. 28. rijna 168, 709 00 Ostrava tel.: +420 591 166 214 fax:+420 596 621 273 mobil: +420 777 093 799 www.linuxbox.cz mobil servis: +420 737 238 656 email servis: ser...@linuxbox.cz - pgpSgK59dAwch.pgp Description: PGP signature
Re: qemu-kvm-1.2.0: double free or corruption in VNC code
On Fri, Nov 23, 2012 at 08:24:32PM +0100, Nikola Ciprich wrote: Please also post the exact package version you are using - the line numbers change between releases and depend on which patches have been applied to the source tree. The distro exact package version allows me to download the source tree that was used to build this binary and check the correct line numbers. Hello Stafan, it's based on fedora rawhide pkg 2:1.2.0-16 with few minor tweaks to compile on centos6. I've uploaded sources used for build here: http://nik.lbox.cz/download/qemu-kvm-1.2.0.tar.bz2 (after make clean) or http://nik.lbox.cz/download/qemu-1.2.0-lb6.01.src.rpm will this help? Thanks, I looked at the backtrace in the source tree. Unfortunately the root cause is not obvious to me. I was looking for a double-free of the zrle buffers. If this bug repeatedly bites you, try a different VNC encoding as a workaround (not ZRLE). Perhaps someone more familiar with the VNC code will be able to see it. All the information you have provided is helpful. Stefan -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: qemu-kvm-1.2.0: double free or corruption in VNC code
Please also post the exact package version you are using - the line numbers change between releases and depend on which patches have been applied to the source tree. The distro exact package version allows me to download the source tree that was used to build this binary and check the correct line numbers. Hello Stafan, it's based on fedora rawhide pkg 2:1.2.0-16 with few minor tweaks to compile on centos6. I've uploaded sources used for build here: http://nik.lbox.cz/download/qemu-kvm-1.2.0.tar.bz2 (after make clean) or http://nik.lbox.cz/download/qemu-1.2.0-lb6.01.src.rpm will this help? Stefan -- - Ing. Nikola CIPRICH LinuxBox.cz, s.r.o. 28. rijna 168, 709 00 Ostrava tel.: +420 591 166 214 fax:+420 596 621 273 mobil: +420 777 093 799 www.linuxbox.cz mobil servis: +420 737 238 656 email servis: ser...@linuxbox.cz - pgp7Roz0brVTP.pgp Description: PGP signature
Re: qemu-kvm-1.2.0: double free or corruption in VNC code
On Wed, Nov 21, 2012 at 07:43:16AM +0100, Nikola Ciprich wrote: Hello Stefan, thanks! here it goes.. *** glibc detected *** /usr/bin/qemu-kvm: double free or corruption (!prev): 0x7fc634008cd0 *** === Backtrace: = /lib64/libc.so.6(+0x75916)[0x7fc9026f4916] /lib64/libc.so.6(+0x78443)[0x7fc9026f7443] /usr/bin/qemu-kvm(+0x1faeb1)[0x7fc907187eb1] /usr/bin/qemu-kvm(+0x1f0e1a)[0x7fc90717de1a] /usr/bin/qemu-kvm(+0x1fb681)[0x7fc907188681] /usr/bin/qemu-kvm(+0xed6a7)[0x7fc90707a6a7] /usr/bin/qemu-kvm(+0x195c31)[0x7fc907122c31] /usr/bin/qemu-kvm(main+0x106c)[0x7fc90711e5fc] /lib64/libc.so.6(__libc_start_main+0xfd)[0x7fc90269dcdd] /usr/bin/qemu-kvm(+0x749f9)[0x7fc9070019f9] [...] [root@blg qemu-kvm-1.2.0]# addr2line -e /usr/lib/debug/usr/bin/qemu-kvm.debug 0x1faeb1 0x1f0e1a 0x1fb681 0xed6a7 0x195c31 0x106c /usr/src/debug/qemu-kvm-1.2.0/ui/vnc.c:499 /usr/src/debug/qemu-kvm-1.2.0/ui/vnc-enc-zrle.c:364 /usr/src/debug/qemu-kvm-1.2.0/ui/vnc.c:1037 /usr/src/debug/qemu-kvm-1.2.0/iohandler.c:159 /usr/src/debug/qemu-kvm-1.2.0/main-loop.c:499 Please also post the exact package version you are using - the line numbers change between releases and depend on which patches have been applied to the source tree. The distro exact package version allows me to download the source tree that was used to build this binary and check the correct line numbers. Stefan -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: qemu-kvm-1.2.0: double free or corruption in VNC code
Hello Stefan, thanks! here it goes.. *** glibc detected *** /usr/bin/qemu-kvm: double free or corruption (!prev): 0x7fc634008cd0 *** === Backtrace: = /lib64/libc.so.6(+0x75916)[0x7fc9026f4916] /lib64/libc.so.6(+0x78443)[0x7fc9026f7443] /usr/bin/qemu-kvm(+0x1faeb1)[0x7fc907187eb1] /usr/bin/qemu-kvm(+0x1f0e1a)[0x7fc90717de1a] /usr/bin/qemu-kvm(+0x1fb681)[0x7fc907188681] /usr/bin/qemu-kvm(+0xed6a7)[0x7fc90707a6a7] /usr/bin/qemu-kvm(+0x195c31)[0x7fc907122c31] /usr/bin/qemu-kvm(main+0x106c)[0x7fc90711e5fc] /lib64/libc.so.6(__libc_start_main+0xfd)[0x7fc90269dcdd] /usr/bin/qemu-kvm(+0x749f9)[0x7fc9070019f9] [...] [root@blg qemu-kvm-1.2.0]# addr2line -e /usr/lib/debug/usr/bin/qemu-kvm.debug 0x1faeb1 0x1f0e1a 0x1fb681 0xed6a7 0x195c31 0x106c /usr/src/debug/qemu-kvm-1.2.0/ui/vnc.c:499 /usr/src/debug/qemu-kvm-1.2.0/ui/vnc-enc-zrle.c:364 /usr/src/debug/qemu-kvm-1.2.0/ui/vnc.c:1037 /usr/src/debug/qemu-kvm-1.2.0/iohandler.c:159 /usr/src/debug/qemu-kvm-1.2.0/main-loop.c:499 ??:0 this makes some sense to me, since it crashed while there was VNC connection active.. It's important to fetch the debuginfo package for the exact same version of the qemu RPM you were running. sure, it's the same version. BR nik -- - Ing. Nikola CIPRICH LinuxBox.cz, s.r.o. 28.rijna 168, 709 00 Ostrava tel.: +420 591 166 214 fax:+420 596 621 273 mobil: +420 777 093 799 www.linuxbox.cz mobil servis: +420 737 238 656 email servis: ser...@linuxbox.cz - pgpCg25xs1tyP.pgp Description: PGP signature
