rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=fcdc/1/0x4000000000000000 softirq=115603/115604 fqs=0 (detected by 1, t=10506 jiffies, g=151433, q=119 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3169 Comm: syz-executor.2 Not tainted 6.1.42-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:__lock_acquire+0x11d8/0x1f80 kernel/locking/lockdep.c:5053 Code: 08 8b 18 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 20 62 49 90 be 08 00 00 00 e8 40 85 76 00 48 0f a3 1d c8 6f df 0e <73> 1b 48 8d 04 5b 48 c1 e0 06 48 8d 98 20 c1 18 90 48 ba 00 00 00 RSP: 0000:ffffc90000007a00 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8169f250 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90496220 RBP: c735c94dd0b594d8 R08: dffffc0000000000 R09: fffffbfff2092c45 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807eb50ad8 R13: ffff88807eb50000 R14: 0000000000000000 R15: 1ffff1100fd6a16a FS: 00007f7bad3dd6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000205b5030 CR3: 000000007c9a3000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 debug_object_deactivate+0x61/0x3f0 lib/debugobjects.c:763 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline] debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:481 __run_hrtimer kernel/time/hrtimer.c:1653 [inline] __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5673 Code: 2b 00 74 08 4c 89 f7 e8 0f 9a 76 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0000:ffffc90005707460 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000ae0e98 RCX: ffffffff816a9365 RDX: dffffc0000000000 RSI: ffffffff8aebe920 RDI: ffffffff8b3cdca0 RBP: ffffc900057075a8 R08: dffffc0000000000 R09: fffffbfff2092c59 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000ae0e94 R13: dffffc0000000000 R14: ffffc900057074c0 R15: 0000000000000246 __mutex_lock_common+0x1d4/0x2520 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 __unix_dgram_recvmsg+0x24d/0x1260 net/unix/af_unix.c:2448 ____sys_recvmsg+0x285/0x530 ___sys_recvmsg net/socket.c:2743 [inline] do_recvmmsg+0x46d/0xad0 net/socket.c:2837 __sys_recvmmsg net/socket.c:2916 [inline] __do_sys_recvmmsg net/socket.c:2939 [inline] __se_sys_recvmmsg net/socket.c:2932 [inline] __x64_sys_recvmmsg+0x195/0x240 net/socket.c:2932 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7bae87cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7bad3dd0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f7bae99c050 RCX: 00007f7bae87cae9 RDX: 00000000040002db RSI: 0000000020000740 RDI: 0000000000000005 RBP: 00007f7bae8c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f7bae99c050 R15: 00007ffc929d91c8 rcu: rcu_preempt kthread starved for 10506 jiffies! g151433 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:26008 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x132c/0x4330 kernel/sched/core.c:6554 schedule+0xbf/0x180 kernel/sched/core.c:6630 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x2c2/0x1010 kernel/rcu/tree.c:1661 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1860 kthread+0x26e/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 3172 Comm: syz-executor.5 Not tainted 6.1.42-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023 RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline] RIP: 0010:smp_call_function_many_cond+0x1f62/0x33d0 kernel/smp.c:987 Code: 2f 44 89 ee 83 e6 01 31 ff e8 4a 19 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 d5 15 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff RSP: 0018:ffffc9000587f520 EFLAGS: 00000293 RAX: ffffffff817ed4fd RBX: 1ffff1101730841d RCX: ffff888049349dc0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000587f8e8 R08: ffffffff817ed4c6 R09: fffffbfff2092c6b R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b98420e8 FS: 00007fd2806ec6c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000280 CR3: 0000000024cdb000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1155 kill_bdev block/bdev.c:75 [inline] set_blocksize+0x2cd/0x350 block/bdev.c:152 sb_set_blocksize+0x45/0xe0 block/bdev.c:161 fat_fill_super+0x24be/0x4d60 fs/fat/inode.c:1682 mount_bdev+0x2c9/0x3f0 fs/super.c:1423 legacy_get_tree+0xeb/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1553 do_new_mount+0x28b/0xae0 fs/namespace.c:3040 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fd27fa7e1ea Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd2806ebee8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fd2806ebf80 RCX: 00007fd27fa7e1ea RDX: 0000000020000540 RSI: 0000000020000580 RDI: 00007fd2806ebf40 RBP: 0000000020000540 R08: 00007fd2806ebf80 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000580 R13: 00007fd2806ebf40 R14: 0000000000000538 R15: 00000000200005c0