1:43 a.m.
On Tue, Oct 9, 2018 at 3:40 AM Jan Kara <jack(a)suse.cz> wrote:
On Fri 05-10-18 17:06:22, Paul Moore wrote:
> On Tue, Sep 4, 2018 at 12:06 PM Jan Kara <jack(a)suse.cz> wrote:
> > Add stress test for stressing audit tree watches by adding and deleting
> > rules while events are generated and watched filesystems are mounted and
> > unmounted in parallel.
> >
> > Signed-off-by: Jan Kara <jack(a)suse.cz>
> > ---
> > tests/stress_tree/Makefile | 8 +++
> > tests/stress_tree/test | 171
+++++++++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 179 insertions(+)
> > create mode 100644 tests/stress_tree/Makefile
> > create mode 100755 tests/stress_tree/test
>
> No commentary on the test itself, other than perhaps it should live
> under test_manual/, but in running the tests in a loop today I am
> reliably able to panic my test kernel after ~30m or so.
Interesting. How do you run the test?
Nothing fancy, just a simple bash loop:
# cd tests/stress_tree
# while ./test; do /bin/true; done
> I'm using the kernel linked below which is Fedora Rawhide +
> selinux/next + audit/next + audit/working-fsnotify_fixes; a link to
> the patches added to the Rawhide kernel can be found in the list
> archive linked below.
>
> * https://groups.google.com/forum/#!topic/kernel-secnext/SFv0d-ij3z8
> * https://copr.fedorainfracloud.org/coprs/pcmoore/kernel-secnext/build/805949
>
> The initial panic dump is below:
I can try to reproduce this but could you perhaps find out which of the
list manipulations in audit_remove_tree_rule() hit the corrution?
A quick dump of the audit_remove_tree_rule() function makes it look
like it is the inner most list_del_init() call.
Dump of assembler code for function audit_remove_tree_rule:
646 {
0xffffffff811ad900 <+0>: callq 0xffffffff81c01850 <__fentry__>
647 struct audit_tree *tree;
648 tree = rule->tree;
0xffffffff811ad905 <+5>: push %r14
0xffffffff811ad907 <+7>: xor %eax,%eax
0xffffffff811ad909 <+9>: push %r13
0xffffffff811ad90b <+11>: push %r12
0xffffffff811ad90d <+13>: push %rbp
0xffffffff811ad90e <+14>: push %rbx
0xffffffff811ad90f <+15>: mov 0x140(%rdi),%rbp
649 if (tree) {
0xffffffff811ad916 <+22>: test %rbp,%rbp
0xffffffff811ad919 <+25>: je 0xffffffff811ad990
<audit_remove_tree_rule+144>
0xffffffff811ad91b <+27>: mov %rdi,%rbx
650 spin_lock(&hash_lock);
651 list_del_init(&rule->rlist);
0xffffffff811ad92a <+42>: lea 0x150(%rbx),%r12
652 if (list_empty(&tree->rules) && !tree->goner) {
653 tree->root = NULL;
0xffffffff811ad999 <+153>: movq $0x0,0x8(%rbp)
654 list_del_init(&tree->same_root);
0xffffffff811ad9a1 <+161>: lea 0x40(%rbp),%r12
655 tree->goner = 1;
0xffffffff811ad9c8 <+200>: lea 0x30(%rbp),%r12
0xffffffff811ad9cc <+204>: movl $0x1,0x4(%rbp)
656 list_move(&tree->list, &prune_list);
657 rule->tree = NULL;
0xffffffff811ada21 <+289>: movq $0x0,0x140(%rbx)
658 spin_unlock(&hash_lock);
659 audit_schedule_prune();
660 return 1;
0xffffffff811ada44 <+324>: mov $0x1,%eax
0xffffffff811ada49 <+329>: pop %rbx
0xffffffff811ada4a <+330>: pop %rbp
0xffffffff811ada4b <+331>: pop %r12
0xffffffff811ada4d <+333>: pop %r13
0xffffffff811ada4f <+335>: pop %r14
0xffffffff811ada51 <+337>: retq
0xffffffff811ada52: data16 nopw %cs:0x0(%rax,%rax,1)
0xffffffff811ada5d: nopl (%rax)
661 }
662 rule->tree = NULL;
0xffffffff811ad974 <+116>: movq $0x0,0x140(%rbx)
663 spin_unlock(&hash_lock);
664 return 1;
0xffffffff811ad98b <+139>: mov $0x1,%eax
0xffffffff811ad990 <+144>: pop %rbx
0xffffffff811ad991 <+145>: pop %rbp
0xffffffff811ad992 <+146>: pop %r12
0xffffffff811ad994 <+148>: pop %r13
0xffffffff811ad996 <+150>: pop %r14
0xffffffff811ad998 <+152>: retq
665 }
666 return 0;
667 }
> [ 139.619065] list_del corruption. prev->next should be
> ffff985fa98d4100, but was ffff985fae91e370
> [ 139.622504] ------------[ cut here ]------------
> [ 139.623402] kernel BUG at lib/list_debug.c:53!
> [ 139.624294] invalid opcode: 0000 [#1] SMP PTI
> [ 139.625439] CPU: 1 PID: 3248 Comm: auditctl Not tainted
> 4.19.0-0.rc6.git2.1.1.secnext.fc30.x86_64 #1
> [ 139.630761] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
> [ 139.631812] RIP: 0010:__list_del_entry_valid.cold.1+0x34/0x4c
> [ 139.632853] Code: ce 34 ac e8 b8 f7 c0 ff 0f 0b 48 c7 c7 a8 cf 34
> ac e8 aa f7 c0 ff 0f 0b 48 89 f2 48 89 fe 48 c7 c7 68 cf 34 ac e8 96
> f7 c0 ff <0f> 0b 48 89 fe 48 c7 c7 30 cf 34 ac e8 85 f7 c0 ff 0f 0b 90
> 90 90
> [ 139.636347] RSP: 0018:ffffb4890293fbb8 EFLAGS: 00010246
> [ 139.637295] RAX: 0000000000000054 RBX: ffff985fae91e620 RCX: 0000000000000000
> [ 139.638573] RDX: 0000000000000000 RSI: ffff985fb77d6be8 RDI: ffff985fb77d6be8
> [ 139.639855] RBP: ffff985fa98d40c0 R08: 00046c1ac1fe8d00 R09: 0000000000000000
> [ 139.641136] R10: 0000000000000000 R11: 0000000000000000 R12: ffff985fa98d4100
> [ 139.642416] R13: 0000000000000000 R14: ffff985faf00fe20 R15: 00000000000003f4
> [ 139.643699] FS: 00007f9898252b80(0000) GS:ffff985fb7600000(0000)
> knlGS:0000000000000000
> [ 139.645199] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 139.646244] CR2: 0000561d333b8218 CR3: 000000023110a000 CR4: 00000000001406e0
> [ 139.647533] Call Trace:
> [ 139.647997] audit_remove_tree_rule+0xad/0x160
> [ 139.648819] audit_del_rule+0x90/0x190
> [ 139.649507] audit_rule_change+0x98e/0xbf0
> [ 139.650259] audit_receive_msg+0x142/0x1160
> [ 139.651030] ? netlink_deliver_tap+0x99/0x410
> [ 139.651832] audit_receive+0x54/0xb0
> [ 139.652495] netlink_unicast+0x181/0x210
> [ 139.653211] netlink_sendmsg+0x218/0x3e0
> [ 139.653936] sock_sendmsg+0x36/0x40
> [ 139.654583] __sys_sendto+0xf1/0x160
> [ 139.655244] ? syscall_trace_enter+0x1d3/0x330
> [ 139.656055] ? trace_hardirqs_off_thunk+0x1a/0x1c
> [ 139.656912] __x64_sys_sendto+0x24/0x30
> [ 139.657615] do_syscall_64+0x60/0x1f0
> [ 139.658285] entry_SYSCALL_64_after_hwframe+0x49/0xbe
> [ 139.659192] RIP: 0033:0x7f989835a7fb
> [ 139.659847] Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3
> 0f 1e fa 48 8d 05 25 6f 0c 00 41 89 ca 8b 00 85 c0 75 14 b8 2c 00 00
> 00 0f 05 <48> 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 41 57 4d 89 c7 41 56
> 41 89
> [ 139.663170] RSP: 002b:00007ffc95ae6b48 EFLAGS: 00000246 ORIG_RAX:
> 000000000000002c
> [ 139.664531] RAX: ffffffffffffffda RBX: 0000000000000460 RCX: 00007f989835a7fb
> [ 139.665809] RDX: 0000000000000460 RSI: 00007ffc95ae6b80 RDI: 0000000000000003
> [ 139.667087] RBP: 0000000000000003 R08: 00007ffc95ae6b6c R09: 000000000000000c
> [ 139.668370] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc95ae6b80
> [ 139.669648] R13: 00007ffc95ae6b6c R14: 0000000000000002 R15: 000000000000044f
> [ 139.670935] Modules linked in: ib_isert iscsi_target_mod ib_srpt
> target_core_mod ib_srp scsi_transport_srp rpcrdma ib_umad rdma_ucm
> ib_iser ib_ipoib rdma_cm iw_cm libiscsi scsi_transport_iscsi ib_cm
> mlx5_ib ib_uverbs ib_core crct10dif_pclmul crc32_pclmul
> ghash_clmulni_intel joydev virtio_balloon i2c_piix4 sunrpc
> drm_kms_helper ttm crc32c_intel mlx5_core drm virtio_console mlxfw
> serio_raw devlink virtio_blk virtio_net net_failover failover
> ata_generic pata_acpi qemu_fw_cfg
> [ 139.678676] ---[ end trace be98f2acb1e536e4 ]---
--
Jan Kara <jack(a)suse.com>
SUSE Labs, CR
--
paul moore
www.paul-moore.com