rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): (detected by 1, t=10502 jiffies, g=375797, q=500) rcu: All QSes seen, last rcu_preempt kthread activity 10445 (4295159905-4295149460), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10445 jiffies! g375797 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:28880 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4681 [inline] __schedule+0x93a/0x26f0 kernel/sched/core.c:5938 schedule+0xd3/0x270 kernel/sched/core.c:6017 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline] rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10304 Comm: syz-executor.3 Not tainted 5.14.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x3ba/0xb40 kernel/locking/qspinlock.c:508 Code: eb c6 45 01 01 41 bc 00 80 00 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 <41> 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 38 d8 7f 08 84 c0 0f RSP: 0018:ffffc90000007a30 EFLAGS: 00000206 RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffffffff18efb14 RDX: 0000000000000001 RSI: ffffffff817bd271 RDI: ffffffff81332591 RBP: ffffffff8c77d8a0 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff817bd239 R11: 0000000000000080 R12: 0000000000001bfd R13: fffffbfff18efb14 R14: 0000000000000001 R15: ffff8880b9c527c0 FS: 00007f8439232700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000540198 CR3: 0000000089029000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113 spin_lock include/linux/spinlock.h:354 [inline] mac80211_hwsim_tx_frame_no_nl.isra.0+0x68f/0x1330 drivers/net/wireless/mac80211_hwsim.c:1516 mac80211_hwsim_tx_frame+0x1ee/0x2a0 drivers/net/wireless/mac80211_hwsim.c:1784 mac80211_hwsim_beacon_tx+0x49b/0x930 drivers/net/wireless/mac80211_hwsim.c:1838 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x70/0x180 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1861 __run_hrtimer kernel/time/hrtimer.c:1537 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1601 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1618 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:finish_task_switch.isra.0+0x23c/0xa50 kernel/sched/core.c:4555 Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 b3 95 e0 07 e8 2e e6 2b 00 fb 65 48 8b 1c 25 00 f0 01 00 <48> 8d bb 10 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc90002bc6740 EFLAGS: 00000202 RAX: 00000000000030d3 RBX: ffff888067638000 RCX: 1ffffffff1fa57c2 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90002bc6780 R08: 0000000000000001 R09: ffffffff8fcf297f R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880b9c519c0 R13: ffff88805e1f8000 R14: 0000000000000000 R15: ffff8880b9c519d8 context_switch kernel/sched/core.c:4684 [inline] __schedule+0x942/0x26f0 kernel/sched/core.c:5938 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6326 irqentry_exit+0x31/0x80 kernel/entry/common.c:427 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_is_held_type+0xfd/0x140 kernel/locking/lockdep.c:5673 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 de 24 d4 76 83 f8 01 75 29 9c 58 f6 c4 02 75 3d 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ed eb b9 0f 0b 48 RSP: 0018:ffffc90002bc6930 EFLAGS: 00000296 RAX: 0000000000000046 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8b97c280 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff83f4ce28 R11: 0000000000000000 R12: ffff888067638000 R13: 0000000000000001 R14: 00000000ffffffff R15: ffff888067638a18 xa_head include/linux/xarray.h:1166 [inline] xas_start+0x220/0x730 lib/xarray.c:188 xas_load+0x28/0x140 lib/xarray.c:233 xa_get_order+0xf7/0x390 lib/xarray.c:1761 __add_to_page_cache_locked+0x4e7/0x1040 mm/filemap.c:884 add_to_page_cache_lru+0x173/0x5c0 mm/filemap.c:967 page_cache_ra_unbounded+0x3ab/0x930 mm/readahead.c:221 do_page_cache_ra mm/readahead.c:267 [inline] ondemand_readahead+0x61e/0x11a0 mm/readahead.c:550 page_cache_async_ra mm/readahead.c:607 [inline] page_cache_async_ra+0x2e1/0x3f0 mm/readahead.c:582 page_cache_async_readahead include/linux/pagemap.h:907 [inline] filemap_readahead mm/filemap.c:2442 [inline] filemap_get_pages+0x61a/0x1940 mm/filemap.c:2483 filemap_read+0x2ca/0xe40 mm/filemap.c:2550 generic_file_read_iter+0x397/0x4f0 mm/filemap.c:2701 ext4_file_read_iter+0x1d4/0x5d0 fs/ext4/file.c:130 __kernel_read+0x58d/0xa90 fs/read_write.c:454 integrity_kernel_read+0x7b/0xb0 security/integrity/iint.c:199 ima_calc_file_hash_tfm+0x2aa/0x3b0 security/integrity/ima/ima_crypto.c:484 ima_calc_file_shash security/integrity/ima/ima_crypto.c:515 [inline] ima_calc_file_hash+0x19d/0x4b0 security/integrity/ima/ima_crypto.c:572 ima_collect_measurement+0x4ca/0x570 security/integrity/ima/ima_api.c:252 process_measurement+0xd1c/0x17e0 security/integrity/ima/ima_main.c:330 ima_file_check+0xb1/0x100 security/integrity/ima/ima_main.c:499 do_open fs/namei.c:3376 [inline] path_openat+0x15ca/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_openat fs/open.c:1236 [inline] __se_sys_openat fs/open.c:1231 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1231 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8439232188 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 0000000000100048 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000074000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffeb3ccf20f R14: 00007f8439232300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: eb c6 jmp 0xffffffc8 2: 45 01 01 add %r8d,(%r9) 5: 41 bc 00 80 00 00 mov $0x8000,%r12d b: 48 c1 e9 03 shr $0x3,%rcx f: 83 e3 07 and $0x7,%ebx 12: 41 be 01 00 00 00 mov $0x1,%r14d 18: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1f: fc ff df 22: 4c 8d 2c 01 lea (%rcx,%rax,1),%r13 26: eb 0c jmp 0x34 28: f3 90 pause 2a: 41 83 ec 01 sub $0x1,%r12d <-- trapping instruction 2e: 0f 84 72 04 00 00 je 0x4a6 34: 41 0f b6 45 00 movzbl 0x0(%r13),%eax 39: 38 d8 cmp %bl,%al 3b: 7f 08 jg 0x45 3d: 84 c0 test %al,%al 3f: 0f .byte 0xf