FYI, we noticed the following commit (built with gcc-7): commit: 5b86d4ff5dce3271dff54119e06174dc22422903 ("afs: Implement network namespacing") https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master in testcase: trinity with following parameters: runtime: 300s test-description: Trinity is a linux system call fuzz tester. test-url: http://codemonkey.org.uk/projects/trinity/ on test machine: qemu-system-x86_64 -enable-kvm -m 512M caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +------------------------------------------------------------------+------------+------------+ | | 1588def91d | 5b86d4ff5d | +------------------------------------------------------------------+------------+------------+ | boot_successes | 31 | 6 | | boot_failures | 4 | 35 | | invoked_oom-killer:gfp_mask=0x | 4 | 2 | | Mem-Info | 4 | 2 | | Out_of_memory:Kill_process | 2 | 2 | | Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes | 2 | 2 | | RIP:copy_fpstate_to_sigframe | 0 | 1 | | BUG:unable_to_handle_kernel | 0 | 33 | | Oops:#[##] | 0 | 33 | | RIP:rxrpc_rcu_destroy_call | 0 | 33 | | Kernel_panic-not_syncing:Fatal_exception_in_interrupt | 0 | 33 | +------------------------------------------------------------------+------------+------------+ [ 20.610136] BUG: unable to handle kernel paging request at ffff880000de4068 [ 20.610841] PGD 40da067 P4D 40da067 PUD 40db067 PMD 1bffa067 PTE 8000000000de4060 [ 20.611550] Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 20.612039] Modules linked in: bochs_drm ttm drm_kms_helper evdev serio_raw drm drm_panel_orientation_quirks cfbfillrect cfbimgblt cfbcopyarea fb_sys_fops syscopyarea sysfillrect sysimgblt fb intel_agp intel_gtt button fbdev agpgart [ 20.613955] CPU: 0 PID: 12 Comm: rcuc/0 Not tainted 4.17.0-rc5-00051-g5b86d4f #1 [ 20.614655] RIP: 0010:rxrpc_rcu_destroy_call+0x39/0x50 [ 20.615136] RSP: 0018:ffffc9000012be08 EFLAGS: 00010286 [ 20.615635] RAX: 0000000080000200 RBX: ffff880000d59700 RCX: 0000000000000201 [ 20.616304] RDX: 0000000080000201 RSI: 000000009f670a10 RDI: 00000000ffffffff [ 20.627094] RBP: ffff880000de4000 R08: 00000000686a9aac R09: 0000000000000001 [ 20.627813] R10: 0000000000000001 R11: 0000000000000000 R12: ffff88001bddfa00 [ 20.628474] R13: ffff88001bddfa38 R14: ffff880000d59700 R15: ffffffff8110333a [ 20.629137] FS: 0000000000000000(0000) GS:ffff88001bc00000(0000) knlGS:0000000000000000 [ 20.629861] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 20.630383] CR2: ffff880000de4068 CR3: 0000000000d67000 CR4: 00000000000006f0 [ 20.631031] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 20.631697] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 20.632358] Call Trace: [ 20.632605] ? rxrpc_process_call+0x820/0x820 [ 20.633015] rcu_do_batch+0x172/0x370 [ 20.633432] rcu_cpu_kthread+0x165/0x170 [ 20.633805] ? smpboot_thread_fn+0x23/0x280 [ 20.634197] ? smpboot_thread_fn+0x6b/0x280 [ 20.634595] smpboot_thread_fn+0x1d3/0x280 [ 20.634981] ? sort_range+0x20/0x20 [ 20.635319] kthread+0x115/0x130 [ 20.635641] ? kthread_create_on_node+0x60/0x60 [ 20.636067] ret_from_fork+0x35/0x40 [ 20.636412] Code: 6e ef 00 00 48 8b bb c8 03 00 00 e8 d2 90 9f ff 48 8b bb d0 03 00 00 e8 c6 90 9f ff 48 8b 3d 67 94 91 02 48 89 de e8 97 91 9f ff <3e> ff 4d 68 74 03 5b 5d c3 48 8d 7d 68 5b 5d e9 e3 0d 92 ff 0f [ 20.648368] RIP: rxrpc_rcu_destroy_call+0x39/0x50 RSP: ffffc9000012be08 [ 20.648981] CR2: ffff880000de4068 [ 20.649307] ---[ end trace 3db688f433278894 ]--- To reproduce: git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, Rong, Chen