We've seen similar reports of (always) smbd getting stuck with our own 4.1.16 kernel: <https://forge.univention.org/bugzilla/show_bug.cgi?id=40558>
The common patch from my research so far looks like "unix: properly account for FDs passed over unix sockets", which might have introduced some suitable locking problem. It has been back-ported from 4.4 to several kernels by now. I'm not able to reproduce the bug with samba3.raw.composite in my 8 vCPU KVM environment. Some time ago I had a similar bug which I could only trigger on real-HW with 8 CPU. ** Bug watch added: forge.univention.org/bugzilla/ #40558 https://forge.univention.org/bugzilla/show_bug.cgi?id=40558 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-lts-trusty in Ubuntu. https://bugs.launchpad.net/bugs/1543980 Title: Kernel 3.13.0-77 crashes (can be triggered by Samba) Status in linux-lts-trusty package in Ubuntu: Confirmed Bug description: Ubuntu 14.04.3 LTS After updating to kernel 3.13.0-77 system crashes. First, network dies, then the whole system. There are several kernel crashes in the logs. --- snip --- ProblemType: KernelOops Annotation: Your system might become unstable now and might need to be restarted. Date: Wed Feb 10 09:20:35 2016 Failure: oops OopsText: BUG: soft lockup - CPU#1 stuck for 23s! [smbd:5908] --- snap --- Followed by kernel stack traces. After some investigation, it turned out that the crash can be triggered by Samba. It's easily reproducible by running the following commands in the Samba master branch: ./configure.developer TDB_NO_FSYNC=1 make -j test FAIL_IMMEDIATELY=1 SOCKET_WRAPPER_KEEP_PCAP=1 TESTS="samba3.raw.composite" Downgrading to kernel 3.13.0-76 solves this problem. Please let me know if we can provide more information or help testing. Thanks! To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-trusty/+bug/1543980/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
