I am seeing same kind of behaviour after upgrade to utopic, mailq fails with permission denied.
The odd thing is it doesn't happen every time. Sometimes when running mailq in a loop it might work occasionally. Sometimes not. Sometimes it works for period of time just fine and then starts failing again. mailq does not have an apparmor profile. audit.log does not show any denied apparmor requests. If I remove all postfix apparmor profiles by apparmor_parser -R, the problem appears to go away. The kernel is 3.16.0-24-generic. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1390223 Title: Apparmor related regression on access to unix sockets on a candidate 3.16 backport kernel Status in “linux” package in Ubuntu: Confirmed Bug description: I recently noticed a bunch of containers failing in a rather odd way when running postfix. The most visible example is when running mailq on an empty queue. Without apparmor (unconfined container) I see that the queue is empty, with apparmor, I get Permission denied. That's all running as root so the permission denied looks a tiny bit odd. Also, running the 3.13 kernel, I don't get any of that weirdness. My guess is that it has to do with the work that went into the 3.16 kernel for socket mediation. In theory only systems that run the utopic apparmor (which I DO NOT) should be seeing that kind of behavior, but it looks like some code path isn't checking things properly :) == strace in unconfined container == chdir("/var/spool/postfix") = 0 rt_sigaction(SIGPIPE, {SIG_IGN, [PIPE], SA_RESTORER|SA_RESTART, 0x7f8963a62c30}, {SIG_IGN, [], 0}, 8) = 0 getuid() = 0 socket(PF_LOCAL, SOCK_STREAM, 0) = 4 fcntl(4, F_GETFL) = 0x2 (flags O_RDWR) fcntl(4, F_SETFL, O_RDWR) = 0 connect(4, {sa_family=AF_LOCAL, sun_path="public/showq"}, 110) = 0 poll([{fd=4, events=POLLIN}], 1, 3600000) = 1 ([{fd=4, revents=POLLIN|POLLHUP}]) read(4, "Mail queue is empty\n", 4096) = 20 poll([{fd=4, events=POLLIN}], 1, 3600000) = 1 ([{fd=4, revents=POLLIN|POLLHUP}]) read(4, "", 4096) = 0 write(1, "Mail queue is empty\n", 20Mail queue is empty ) = 20 close(4) = 0 exit_group(0) = ? +++ exited with 0 +++ == strace in confined container == chdir("/var/spool/postfix") = 0 rt_sigaction(SIGPIPE, {SIG_IGN, [PIPE], SA_RESTORER|SA_RESTART, 0x7ffe62de4c30}, {SIG_IGN, [], 0}, 8) = 0 getuid() = 0 socket(PF_LOCAL, SOCK_STREAM, 0) = 4 fcntl(4, F_GETFL) = 0x2 (flags O_RDWR) fcntl(4, F_SETFL, O_RDWR) = 0 connect(4, {sa_family=AF_LOCAL, sun_path="public/showq"}, 110) = 0 poll([{fd=4, events=POLLIN}], 1, 3600000) = 1 ([{fd=4, revents=POLLIN|POLLHUP}]) read(4, 0x7ffe65b35c00, 4096) = -1 EACCES (Permission denied) close(4) = 0 write(2, "postqueue: warning: close: Permi"..., 45postqueue: warning: close: Permission denied ) = 45 sendto(3, "<20>Nov 6 20:40:42 postfix/post"..., 78, MSG_NOSIGNAL, NULL, 0) = 78 exit_group(0) = ? Kernel is a slightly outdated version of the kernel from the kernel team PPA: Linux shell01 3.16.0-23-generic #31-Ubuntu SMP Thu Oct 23 20:13:35 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux If you think the latest build will improve this, I can test it, but seeing how this is a production server, I can't just flip kernels every 5 minutes (I'm running 3.16 to avoid a nasty btrfs bug on 3.13). To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1390223/+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
