Greeting, FYI, we noticed the following commit (built with gcc-9): commit: 995fe757ecaeac44e023458af64d27655f9dbf73 ("[PATCH] device property: Check fwnode->secondary when finding properties") url: https://github.com/0day-ci/linux/commits/Daniel-Scally/device-property-Ch... base: https://git.kernel.org/cgit/linux/kernel/git/gregkh/driver-core.git b5013d084e03e82ceeab4db8ae8ceeaebe76b0eb patch link: https://lore.kernel.org/lkml/20211113204141.520924-1-djrscally@gmail.com in testcase: boot on test machine: qemu-system-i386 -enable-kvm -cpu SandyBridge -smp 2 -m 4G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +---------------------------------------------+------------+------------+ | | b5013d084e | 995fe757ec | +---------------------------------------------+------------+------------+ | boot_successes | 23 | 0 | | boot_failures | 0 | 22 | | BUG:kernel_NULL_pointer_dereference,address | 0 | 22 | | Oops:#[##] | 0 | 22 | | EIP:fwnode_property_get_reference_args | 0 | 22 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 22 | +---------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot <oliver.sang(a)intel.com&gt; [ 17.327851][ T7] BUG: kernel NULL pointer dereference, address: 00000000 [ 17.329758][ T7] #PF: supervisor read access in kernel mode [ 17.331371][ T7] #PF: error_code(0x0000) - not-present page [ 17.332992][ T7] *pde = 00000000 [ 17.334107][ T7] Oops: 0000 [#1] PREEMPT [ 17.335310][ T7] CPU: 0 PID: 7 Comm: kworker/u2:0 Tainted: G S 5.15.0-11191-g995fe757ecae #1 [ 17.338036][ T7] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 [ 17.340544][ T7] Workqueue: events_unbound deferred_probe_work_func [ 17.342291][ T7] EIP: fwnode_property_get_reference_args (drivers/base/property.c:486 (discriminator 1)) [ 17.344051][ T7] Code: 8b 45 0c 50 8b 45 08 50 89 d8 89 55 f4 ff d6 83 c4 0c 89 c6 85 c0 78 55 8d 65 f8 89 f0 5b 5e 5d c3 8d 74 26 00 be fa ff ff ff <8b> 03 85 c0 74 e8 3d 00 f0 ff ff 77 e1 8b 58 04 85 db 74 37 8b 5b All code ======== 0: 8b 45 0c mov 0xc(%rbp),%eax 3: 50 push %rax 4: 8b 45 08 mov 0x8(%rbp),%eax 7: 50 push %rax 8: 89 d8 mov %ebx,%eax a: 89 55 f4 mov %edx,-0xc(%rbp) d: ff d6 callq *%rsi f: 83 c4 0c add $0xc,%esp 12: 89 c6 mov %eax,%esi 14: 85 c0 test %eax,%eax 16: 78 55 js 0x6d 18: 8d 65 f8 lea -0x8(%rbp),%esp 1b: 89 f0 mov %esi,%eax 1d: 5b pop %rbx 1e: 5e pop %rsi 1f: 5d pop %rbp 20: c3 retq 21: 8d 74 26 00 lea 0x0(%rsi,%riz,1),%esi 25: be fa ff ff ff mov $0xfffffffa,%esi 2a:* 8b 03 mov (%rbx),%eax <-- trapping instruction 2c: 85 c0 test %eax,%eax 2e: 74 e8 je 0x18 30: 3d 00 f0 ff ff cmp $0xfffff000,%eax 35: 77 e1 ja 0x18 37: 8b 58 04 mov 0x4(%rax),%ebx 3a: 85 db test %ebx,%ebx 3c: 74 37 je 0x75 3e: 8b .byte 0x8b 3f: 5b pop %rbx Code starting with the faulting instruction =========================================== 0: 8b 03 mov (%rbx),%eax 2: 85 c0 test %eax,%eax 4: 74 e8 je 0xffffffffffffffee 6: 3d 00 f0 ff ff cmp $0xfffff000,%eax b: 77 e1 ja 0xffffffffffffffee d: 8b 58 04 mov 0x4(%rax),%ebx 10: 85 db test %ebx,%ebx 12: 74 37 je 0x4b 14: 8b .byte 0x8b 15: 5b pop %rbx [ 17.350847][ T7] EAX: 00000000 EBX: 00000000 ECX: 00000000 EDX: c37cd6d8 [ 17.352783][ T7] ESI: ffffffea EDI: f5b5a400 EBP: c4cffd24 ESP: c4cffd14 [ 17.354673][ T7] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 EFLAGS: 00010246 [ 17.362075][ T7] CR0: 80050033 CR2: 00000000 CR3: 04206000 CR4: 00000690 [ 17.363993][ T7] Call Trace: [ 17.365018][ T7] fwnode_find_reference (drivers/base/property.c:514) [ 17.366430][ T7] ? __this_cpu_preempt_check (lib/smp_processor_id.c:67) [ 17.367825][ T7] ? lockdep_init_map_type (kernel/locking/lockdep.c:4813) [ 17.369325][ T7] ? phylink_run_resolve+0x20/0x20 [ 17.370897][ T7] ? init_timer_key (kernel/time/timer.c:818) [ 17.372228][ T7] fwnode_get_phy_node (drivers/net/phy/phy_device.c:2986) [ 17.373574][ T7] phylink_fwnode_phy_connect (drivers/net/phy/phylink.c:1180 drivers/net/phy/phylink.c:1166) [ 17.375014][ T7] phylink_of_phy_connect (drivers/net/phy/phylink.c:1152) [ 17.376373][ T7] dsa_slave_create (net/dsa/slave.c:1889 net/dsa/slave.c:2036) [ 17.377765][ T7] dsa_tree_setup_switches (net/dsa/dsa2.c:477 net/dsa/dsa2.c:977) [ 17.379282][ T7] dsa_register_switch (net/dsa/dsa2.c:1065 net/dsa/dsa2.c:1565 net/dsa/dsa2.c:1579) [ 17.380762][ T7] dsa_loop_drv_probe (drivers/net/dsa/dsa_loop.c:333) [ 17.382137][ T7] mdio_probe (drivers/net/phy/mdio_device.c:157) [ 17.383362][ T7] really_probe (drivers/base/dd.c:744) [ 17.384808][ T7] really_probe (drivers/base/dd.c:678) [ 17.385999][ T7] __driver_probe_device (drivers/base/dd.c:751) [ 17.387393][ T7] driver_probe_device (drivers/base/dd.c:781) [ 17.388787][ T7] __device_attach_driver (drivers/base/dd.c:899) [ 17.390253][ T7] ? driver_allows_async_probing (drivers/base/dd.c:867) [ 17.391829][ T7] bus_for_each_drv (drivers/base/bus.c:427) [ 17.393226][ T7] __device_attach (drivers/base/dd.c:969) [ 17.394610][ T7] ? driver_allows_async_probing (drivers/base/dd.c:867) [ 17.396270][ T7] device_initial_probe (drivers/base/dd.c:1017) [ 17.397637][ T7] bus_probe_device (drivers/base/bus.c:487) [ 17.398907][ T7] deferred_probe_work_func (drivers/base/dd.c:123) [ 17.400385][ T7] process_one_work (arch/x86/include/asm/jump_label.h:41 include/linux/jump_label.h:212 include/trace/events/workqueue.h:108 kernel/workqueue.c:2303) [ 17.401834][ T7] worker_thread (include/linux/list.h:282 kernel/workqueue.c:2358 kernel/workqueue.c:2450) [ 17.403204][ T7] kthread (kernel/kthread.c:327) [ 17.404417][ T7] ? process_one_work (kernel/workqueue.c:2388) [ 17.405766][ T7] ? set_kthread_struct (kernel/kthread.c:272) [ 17.407168][ T7] ret_from_fork (arch/x86/entry/entry_32.S:775) [ 17.408421][ T7] Modules linked in: [ 17.409637][ T7] CR2: 0000000000000000 [ 17.410743][ T7] ---[ end trace f8ecb8c3f56e69be ]--- [ 17.412229][ T7] EIP: fwnode_property_get_reference_args (drivers/base/property.c:486 (discriminator 1)) [ 17.414104][ T7] Code: 8b 45 0c 50 8b 45 08 50 89 d8 89 55 f4 ff d6 83 c4 0c 89 c6 85 c0 78 55 8d 65 f8 89 f0 5b 5e 5d c3 8d 74 26 00 be fa ff ff ff <8b> 03 85 c0 74 e8 3d 00 f0 ff ff 77 e1 8b 58 04 85 db 74 37 8b 5b All code ======== 0: 8b 45 0c mov 0xc(%rbp),%eax 3: 50 push %rax 4: 8b 45 08 mov 0x8(%rbp),%eax 7: 50 push %rax 8: 89 d8 mov %ebx,%eax a: 89 55 f4 mov %edx,-0xc(%rbp) d: ff d6 callq *%rsi f: 83 c4 0c add $0xc,%esp 12: 89 c6 mov %eax,%esi 14: 85 c0 test %eax,%eax 16: 78 55 js 0x6d 18: 8d 65 f8 lea -0x8(%rbp),%esp 1b: 89 f0 mov %esi,%eax 1d: 5b pop %rbx 1e: 5e pop %rsi 1f: 5d pop %rbp 20: c3 retq 21: 8d 74 26 00 lea 0x0(%rsi,%riz,1),%esi 25: be fa ff ff ff mov $0xfffffffa,%esi 2a:* 8b 03 mov (%rbx),%eax <-- trapping instruction 2c: 85 c0 test %eax,%eax 2e: 74 e8 je 0x18 30: 3d 00 f0 ff ff cmp $0xfffff000,%eax 35: 77 e1 ja 0x18 37: 8b 58 04 mov 0x4(%rax),%ebx 3a: 85 db test %ebx,%ebx 3c: 74 37 je 0x75 3e: 8b .byte 0x8b 3f: 5b pop %rbx Code starting with the faulting instruction =========================================== 0: 8b 03 mov (%rbx),%eax 2: 85 c0 test %eax,%eax 4: 74 e8 je 0xffffffffffffffee 6: 3d 00 f0 ff ff cmp $0xfffff000,%eax b: 77 e1 ja 0xffffffffffffffee d: 8b 58 04 mov 0x4(%rax),%ebx 10: 85 db test %ebx,%ebx 12: 74 37 je 0x4b 14: 8b .byte 0x8b 15: 5b pop %rbx To reproduce: # build kernel cd linux cp config-5.15.0-11191-g995fe757ecae .config make HOSTCC=gcc-9 CC=gcc-9 ARCH=i386 olddefconfig prepare modules_prepare bzImage git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k <bzImage> job-script # job-script is attached in this email # if come across any failure that blocks the test, # please remove ~/.lkp and /lkp dir to run from a clean state. --- 0DAY/LKP+ Test Infrastructure Open Source Technology Center https://lists.01.org/hyperkitty/list/lkp@lists.01.org Intel Corporation Thanks, Oliver Sang