FYI, we noticed the following commit (built with gcc-6): commit: 6c2f08915886cda1668ace606660f72917ce1f71 ("Refactor part of the oom report in dump_header") ERROR# 1: 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 -cpu host -smp 2 -m 1G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +------------------------------------------------------------------+------------+------------+ | | bee797529d | 6c2f089158 | +------------------------------------------------------------------+------------+------------+ | boot_successes | 4 | 3 | | boot_failures | 12 | 13 | | invoked_oom-killer:gfp_mask=0x | 12 | 12 | | Mem-Info | 12 | 1 | | Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes | 12 | | | BUG:KASAN:null-ptr-deref_in_m | 0 | 12 | | BUG:unable_to_handle_kernel | 0 | 12 | | Oops:#[##] | 0 | 12 | | RIP:mem_cgroup_print_oom_context | 0 | 12 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 12 | | Out_of_memory:Kill_process | 0 | 1 | +------------------------------------------------------------------+------------+------------+ [ 43.710081] BUG: KASAN: null-ptr-deref in mem_cgroup_print_oom_context+0x90/0x203 [ 43.710674] Read of size 8 at addr 0000000000000710 by task swapper/0/1 [ 43.713611] [ 43.713611] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.17.0-rc6-00159-g6c2f089 #1 [ 43.713611] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 43.713611] Call Trace: [ 43.713611] show_stack+0x6e/0x71 [ 43.713611] dump_stack+0x133/0x1c8 [ 43.713611] ? mem_cgroup_print_oom_context+0x90/0x203 [ 43.713611] kasan_report+0x313/0x35d [ 43.713611] __asan_load8+0x7f/0x81 [ 43.723539] mem_cgroup_print_oom_context+0x90/0x203 [ 43.723539] dump_header+0x149/0x4cc [ 43.723539] out_of_memory+0x5a1/0x665 [ 43.723539] ? unregister_oom_notifier+0x1a/0x1a [ 43.723539] ? __alloc_pages_slowpath+0x119c/0x184f [ 43.723539] __alloc_pages_slowpath+0x13dc/0x184f [ 43.723539] ? get_page_from_freelist+0x17ba/0x18cf [ 43.723539] ? __alloc_pages_cpuset_fallback+0x74/0x74 [ 43.733564] ? __asan_loadN+0xf/0x11 [ 43.733564] __alloc_pages_nodemask+0x384/0x560 [ 43.733564] ? __alloc_pages_slowpath+0x184f/0x184f [ 43.733564] ? _find_next_bit+0x12f/0x1be [ 43.733564] ? __asan_loadN+0xf/0x11 [ 43.733564] ? trace_irq_enable_rcuidle+0x3a/0x117 [ 43.733564] cache_grow_begin+0xe0/0x45e [ 43.733564] fallback_alloc+0x1f3/0x27d [ 43.733564] ____cache_alloc_node+0x16e/0x17b [ 43.743553] kmem_cache_alloc_trace+0xe7/0x20f [ 43.743553] maybe_link+0x1ff/0x307 [ 43.743553] do_name+0x10a/0x507 [ 43.743553] ? write_buffer+0x31/0x4c [ 43.743553] write_buffer+0x39/0x4c [ 43.743553] flush_buffer+0x63/0x143 [ 43.743553] __gunzip+0x65a/0x82e [ 43.743553] ? decompress_method+0x147/0x147 [ 43.743553] ? error+0x51/0x51 [ 43.753558] gunzip+0x11/0x13 [ 43.753558] ? do_start+0x23/0x23 [ 43.753558] unpack_to_rootfs+0x2d8/0x5b5 [ 43.753558] ? do_start+0x23/0x23 [ 43.753558] ? printk+0x3a/0xc3 [ 43.753558] ? __gunzip+0x82e/0x82e [ 43.753558] ? do_collect+0xc7/0xc7 [ 43.753558] populate_rootfs+0xf4/0x2fd [ 43.753558] ? unpack_to_rootfs+0x5b5/0x5b5 [ 43.763573] do_one_initcall+0x1bf/0x47d [ 43.763573] ? start_kernel+0x7f2/0x7f2 [ 43.763573] ? __asan_loadN+0xf/0x11 [ 43.763573] ? __asan_loadN+0xf/0x11 [ 43.763573] ? do_early_param+0x119/0x119 [ 43.763573] kernel_init_freeable+0x1d4/0x2e7 [ 43.763573] ? rest_init+0xdd/0xdd [ 43.763573] kernel_init+0x11/0x20e [ 43.773471] ? rest_init+0xdd/0xdd [ 43.773566] ret_from_fork+0x24/0x30 [ 43.773566] ================================================================== [ 43.773566] Disabling lock debugging due to kernel taint [ 43.780696] BUG: unable to handle kernel NULL pointer dereference at 0000000000000710 [ 43.782654] PGD 0 P4D 0 [ 43.783382] Oops: 0000 [#1] SMP KASAN PTI [ 43.783737] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G B 4.17.0-rc6-00159-g6c2f089 #1 [ 43.783737] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 43.783737] RIP: 0010:mem_cgroup_print_oom_context+0x90/0x203 [ 43.783737] RSP: 0000:ffff88000f4d7648 EFLAGS: 00010296 [ 43.793615] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff812d6701 [ 43.793615] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000246 [ 43.793615] RBP: ffff88000f4d7678 R08: fffffbfff0f2c7e4 R09: fffffbfff0f2c7e3 [ 43.793615] R10: 0000000000000000 R11: ffffffff87963f1f R12: 0000000000000000 [ 43.793615] R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 [ 43.793615] FS: 0000000000000000(0000) GS:ffff88002cd00000(0000) knlGS:0000000000000000 [ 43.803595] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 43.803595] CR2: 0000000000000710 CR3: 0000000006236000 CR4: 00000000000006e0 [ 43.803595] Call Trace: [ 43.803595] dump_header+0x149/0x4cc [ 43.803595] out_of_memory+0x5a1/0x665 [ 43.803595] ? unregister_oom_notifier+0x1a/0x1a [ 43.803595] ? __alloc_pages_slowpath+0x119c/0x184f [ 43.803595] __alloc_pages_slowpath+0x13dc/0x184f [ 43.803595] ? get_page_from_freelist+0x17ba/0x18cf [ 43.813619] ? __alloc_pages_cpuset_fallback+0x74/0x74 [ 43.813619] ? __asan_loadN+0xf/0x11 [ 43.813619] __alloc_pages_nodemask+0x384/0x560 [ 43.813619] ? __alloc_pages_slowpath+0x184f/0x184f [ 43.813619] ? _find_next_bit+0x12f/0x1be [ 43.813619] ? __asan_loadN+0xf/0x11 [ 43.813619] ? trace_irq_enable_rcuidle+0x3a/0x117 [ 43.813619] cache_grow_begin+0xe0/0x45e [ 43.813619] fallback_alloc+0x1f3/0x27d [ 43.813619] ____cache_alloc_node+0x16e/0x17b [ 43.823627] kmem_cache_alloc_trace+0xe7/0x20f [ 43.823627] maybe_link+0x1ff/0x307 [ 43.823627] do_name+0x10a/0x507 [ 43.823627] ? write_buffer+0x31/0x4c [ 43.823627] write_buffer+0x39/0x4c [ 43.823627] flush_buffer+0x63/0x143 [ 43.823627] __gunzip+0x65a/0x82e [ 43.823627] ? decompress_method+0x147/0x147 [ 43.823627] ? error+0x51/0x51 [ 43.823627] gunzip+0x11/0x13 [ 43.833595] ? do_start+0x23/0x23 [ 43.833595] unpack_to_rootfs+0x2d8/0x5b5 [ 43.833595] ? do_start+0x23/0x23 [ 43.833595] ? printk+0x3a/0xc3 [ 43.833595] ? __gunzip+0x82e/0x82e [ 43.833595] ? do_collect+0xc7/0xc7 [ 43.833595] populate_rootfs+0xf4/0x2fd [ 43.833595] ? unpack_to_rootfs+0x5b5/0x5b5 [ 43.833595] do_one_initcall+0x1bf/0x47d [ 43.833595] ? start_kernel+0x7f2/0x7f2 [ 43.833595] ? __asan_loadN+0xf/0x11 [ 43.843603] ? __asan_loadN+0xf/0x11 [ 43.843603] ? do_early_param+0x119/0x119 [ 43.843603] kernel_init_freeable+0x1d4/0x2e7 [ 43.843603] ? rest_init+0xdd/0xdd [ 43.843603] kernel_init+0x11/0x20e [ 43.843603] ? rest_init+0xdd/0xdd [ 43.843603] ret_from_fork+0x24/0x30 [ 43.843603] Code: e8 45 33 ff ff 49 8b bd 10 01 00 00 b9 00 10 00 00 48 c7 c2 c0 c8 a8 88 31 f6 e8 3b 69 12 00 48 8d bb 10 07 00 00 e8 1f 33 ff ff <4c> 8b ab 10 07 00 00 49 8d 7d 10 e8 0f 33 ff ff 4d 8b 6d 10 4c [ 43.853611] RIP: mem_cgroup_print_oom_context+0x90/0x203 RSP: ffff88000f4d7648 [ 43.853611] CR2: 0000000000000710 [ 43.853611] random: get_random_bytes called from init_oops_id+0x51/0x64 with crng_init=0 [ 43.853611] ---[ end trace 0d0e0f91afa36bfe ]--- 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, Xiaolong