Re: Kernel oops+crash on repeated auditd restarts

Here's a trace with debugging turned way up plus a few extra printk's added to fs/notify/mark.c. I'm looping through private_destroy_list before and after the call to synchronize_srcu. I can reproduce this reliably with kvm with 2 virtual processors: Linux desktop 3.4.0-rc3-oops1+ #1 SMP Tue Apr 17 09:59:44 PDT 2012 x86_64 GNU/Linux Cheers, peter On Thu, Apr 5, 2012 at 2:07 PM, Eric Paris <eparis(a)redhat.com&gt; wrote: > please please please keep on list.  Everything you say might help track > it down! > > On Thu, 2012-04-05 at 14:03 -0700, Peter Moody wrote: >> (please let me know if I should take this off-list) >> >> One other thing (again, maybe already known), but this seems to be >> exacerbated by SMP. On my machine, I can't reproduce the crash if I >> booth with maxcpus=1. >> >> Still hunting. >> >> Cheers, >> peter >> >> On Tue, Apr 3, 2012 at 9:15 AM, Peter Moody <pmoody(a)google.com&gt; wrote: >> > This may already be known, but the issue seems to be limited to watch >> > rules. With any watch rules, I can reliably crash my machine while >> > freeing a watch rule after only starting/stopping auditd a few times. >> > With no watch rules, I have no issues. >> > >> > Cheers, >> > peter >> > >> > On Wed, Mar 28, 2012 at 11:44 PM, Valentin Avram <aval13(a)gmail.com&gt; wrote: >> >> Yes, i know that patch. It made it into kernel 3.2.2. I tested it >> >> successfully (oops in 3.2.1, no oops in 3.2.9), but this oops i'm seeing is >> >> also in 3.2.9. >> >> >> >> I monitored changelogs since 3.2.1 to 3.2.12 but there were no fixes either >> >> in audit subsystem or in fsnotify. I'll try to reproduce in latest 3.2.13 >> >> and repost the oops, but i'm 99% confident it will be the same. >> >> >> >> Sadly nobody except you seems to pay attention to this problem, probably >> >> because it requires special conditions to reproduce (really, who starts and >> >> stops auditd every 5 seconds on a production server?). We only ran into it >> >> because one of our servers would randomly oops and then freeze about each >> >> month after stopping and then starting >> >> >> >> auditd >> >> >> >> every morning (and the stop-start sequence was needed to workaround a bug >> >> somewhere that would hang a >> >> >> >> gzip >> >> >> >> running on a file outside a watched folder). >> >> >> >> Anyway, as a last note, i have a feeling that the oops is not exactly >> >> random, there is a pattern, just that i haven't figured it out completely >> >> yet. >> >> >> >> Will keep you >> >> >> >> uptodate >> >> >> >> with the things i find out. >> >> >> >> V. >> >> >> >> On Mar 29, 2012 4:14 AM, "Eric Paris" <eparis(a)redhat.com&gt; wrote: >> >>> >> >>> That patch fixes a BUG() .  The report has a NULL ptr deref and some >> >>> apparent list correuption....  Sadly they aren't the same.... >> >>> >> >>> On Wed, 2012-03-28 at 15:42 -0700, Peter Moody wrote: >> >>> > fyi: this patch [1] seems to fix the issue for me. The explanation in >> >>> > the subject would reliably oops my machine. >> >>> > >> >>> > [1] >> >>> > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit... >> >>> > >> >>> > On Wed, Mar 28, 2012 at 1:51 PM, Peter Moody <pmoody(a)google.com&gt; wrote: >> >>> > > Are you still able to reliably reproduce this oops? I'm trying to >> >>> > > track this down because this bug (or a very similar bug) is causing >> >>> > > some significant headaches here at work, but I haven't had a lot of >> >>> > > luck. I'm using usermode linux, though, so that might be interfering >> >>> > > with things. >> >>> > > >> >>> > > On Mon, Mar 5, 2012 at 12:35 AM, Valentin Avram <aval13(a)gmail.com&gt; >> >>> > > wrote: >> >>> > >> Finally i found some time and spare server to retest the oops and >> >>> > >> list_add >> >>> > >> corruptions i was getting with the 3.x kernels and auditd 2.1.3. >> >>> > >> >> >>> > >> I tested now with gentoo's latest stable 3.2.1-gentoo-r2 and >> >>> > >> kernel.org's >> >>> > >> 3.2.9. >> >>> > >> >> >>> > >> Both get the oops/BUG in the same way and after that, they keep >> >>> > >> pouring >> >>> > >> list_add corruptions with audit_prune_tre(truncated?) and auditctl as >> >>> > >> comms. >> >>> > >> >> >>> > >> Since this is not about Gentoo's kernel only, i'll post here the oops >> >>> > >> in >> >>> > >> 3.2.9 and also attach some list_add corruptions. >> >>> > >> >> >>> > >> 3.2.9 BUG: >> >>> > >> >> >>> > >> kernel: [  301.240011] BUG: unable to handle kernel NULL pointer >> >>> > >> dereference >> >>> > >> at   (null) >> >>> > >> kernel: [  301.240305] IP: [<c1238dd0>] __list_del_entry+0x20/0xe0 >> >>> > >> kernel: [  301.240481] *pdpt = 0000000000000000 *pde = >> >>> > >> f000ddc8f000ddc8 >> >>> > >> kernel: [  301.240698] Oops: 0000 [#1] SMP >> >>> > >> kernel: [  301.240910] >> >>> > >> kernel: [  301.241030] Pid: 642, comm: fsnotify_mark Not tainted >> >>> > >> 3.2.9-drbd-version3 #1 Dell Inc. PowerEdge 2950/0CX396 >> >>> > >> kernel: [  301.241370] EIP: 0060:[<c1238dd0>] EFLAGS: 00010287 CPU: 6 >> >>> > >> kernel: [  301.241498] EIP is at __list_del_entry+0x20/0xe0 >> >>> > >> kernel: [  301.241623] EAX: f4fae544 EBX: f47cffa4 ECX: ffffffff EDX: >> >>> > >> 00000000 >> >>> > >> kernel: [  301.241751] ESI: f4fae544 EDI: f4fae508 EBP: f47cff7c ESP: >> >>> > >> f47cff64 >> >>> > >> kernel: [  301.241879]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 >> >>> > >> kernel: [  301.242005] Process fsnotify_mark (pid: 642, ti=f47ce000 >> >>> > >> task=f4f47c00 task.ti=f47ce000) >> >>> > >> kernel: [  301.242207] Stack: >> >>> > >> kernel: [  301.242327]  c10813c0 f47cffa4 f4f47c00 f4e70888 f47cff7c >> >>> > >> f47cffa4 f47cffb8 c10f6976 >> >>> > >> kernel: [  301.242882]  ffffffc3 f4f47c00 f4f47c00 00000000 f4f47c00 >> >>> > >> c10530c0 f47cff9c f47cff9c >> >>> > >> kernel: [  301.243438]  f4fae544 f4fae544 f4c47f58 00000000 c10f68f0 >> >>> > >> f47cffe4 c1052834 00000000 >> >>> > >> kernel: [  301.243995] Call Trace: >> >>> > >> kernel: [  301.244119]  [<c10813c0>] ? >> >>> > >> rcu_check_callbacks+0x110/0x110 >> >>> > >> kernel: [  301.244248]  [<c10f6976>] fsnotify_mark_destroy+0x86/0x120 >> >>> > >> kernel: [  301.244377]  [<c10530c0>] ? abort_exclusive_wait+0x80/0x80 >> >>> > >> kernel: [  301.244504]  [<c10f68f0>] ? fsnotify_put_mark+0x30/0x30 >> >>> > >> kernel: [  301.244631]  [<c1052834>] kthread+0x74/0x80 >> >>> > >> kernel: [  301.244756]  [<c10527c0>] ? >> >>> > >> kthread_flush_work_fn+0x10/0x10 >> >>> > >> kernel: [  301.244885]  [<c1582ab6>] kernel_thread_helper+0x6/0xd >> >>> > >> kernel: [  301.245011] Code: 55 f4 8b 45 f8 e9 75 ff ff ff 90 55 89 >> >>> > >> e5 53 83 >> >>> > >> ec 14 8b 08 8b 50 04 81 f9 00 01 10 00 74 24 81 fa 00 02 20 00 0f 84 >> >>> > >> 8e 00 >> >>> > >> 00 00 <8b> 1a 39 d8 75 62 8b 59 04 39 d8 75 35 89 51 04 89 0a 83 c4 >> >>> > >> 14 >> >>> > >> kernel: [  301.248195] EIP: [<c1238dd0>] __list_del_entry+0x20/0xe0 >> >>> > >> SS:ESP >> >>> > >> 0068:f47cff64 >> >>> > >> kernel: [  301.248414] CR2: 0000000000000000 >> >>> > >> kernel: [  301.248538] ---[ end trace 15082dbfb353f84c ]--- >> >>> > >> >> >>> > >> The kernel was compiled with the following DEBUG support (the bolded >> >>> > >> one >> >>> > >> were requested by Gentoo's Dev: >> >>> > >> CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC=y >> >>> > >> CONFIG_SLUB_DEBUG=y >> >>> > >> CONFIG_HAVE_DMA_API_DEBUG=y >> >>> > >> CONFIG_X86_DEBUGCTLMSR=y >> >>> > >> CONFIG_PNP_DEBUG_MESSAGES=y >> >>> > >> CONFIG_AIC94XX_DEBUG=y >> >>> > >> CONFIG_USB_DEBUG=y >> >>> > >> CONFIG_DEBUG_KERNEL=y >> >>> > >> CONFIG_SCHED_DEBUG=y >> >>> > >> CONFIG_DEBUG_RT_MUTEXES=y >> >>> > >> CONFIG_DEBUG_PI_LIST=y >> >>> > >> CONFIG_DEBUG_BUGVERBOSE=y >> >>> > >> CONFIG_DEBUG_INFO=y >> >>> > >> CONFIG_DEBUG_MEMORY_INIT=y >> >>> > >> CONFIG_DEBUG_LIST=y >> >>> > >> CONFIG_DEBUG_STACKOVERFLOW=y >> >>> > >> CONFIG_DEBUG_RODATA=y >> >>> > >> CONFIG_DEBUG_RODATA_TEST=y >> >>> > >> >> >>> > >> I attached the kernel config i used for 3.2.9 to generate this oops >> >>> > >> and >> >>> > >> warnings. >> >>> > >> >> >>> > >> From the list_add warnings that come after, out of 805 warnings i >> >>> > >> processed, >> >>> > >> after masking with XXXXX the PID and next= values that kept changing >> >>> > >> in >> >>> > >> every one, i got 26 types of MD5. I also attached the files relevant >> >>> > >> as an >> >>> > >> archive to this email. >> >>> > >> >> >>> > >> The Gentoo bug i opened is sleeping, it seems nobody has the time to >> >>> > >> at >> >>> > >> least test to confirm or not the problems i'm seeing (or everybody's >> >>> > >> thinking that nobody would restart auditd so often, so the bug it's >> >>> > >> not that >> >>> > >> serious). >> >>> > >> >> >>> > >> >> >>> > >> Thank you for your time. >> >>> > >> >> >>> > >> On Wed, Feb 8, 2012 at 6:11 PM, Valentin Avram <aval13(a)gmail.com&gt; >> >>> > >> wrote: >> >>> > >> >> >>> > >> >> >>> > >> -- >> >>> > >> Linux-audit mailing list >> >>> > >> Linux-audit(a)redhat.com >> >>> > >> https://www.redhat.com/mailman/listinfo/linux-audit >> >>> > > >> >>> > > >> >>> > > >> >>> > > -- >> >>> > > Peter Moody      Google    1.650.253.7306 >> >>> > > Security Engineer  pgp:0xC3410038 >> >>> > >> >>> > >> >>> > >> >>> >> >>> >> >> >> > >> > >> > >> > -- >> > Peter Moody      Google    1.650.253.7306 >> > Security Engineer  pgp:0xC3410038 >> >> >> > > -- Peter Moody      Google    1.650.253.7306 Security Engineer  pgp:0xC3410038