rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5114/1:b..l rcu: (detected by 0, t=10503 jiffies, g=26205, q=477 ncpus=2) task:syz-executor.3 state:R running task stack:23920 pid:5114 tgid:5114 ppid:5098 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7067 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__sanitizer_cov_trace_pc+0x33/0x60 kernel/kcov.c:207 Code: f3 75 7e 65 8b 05 e5 f3 75 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 35 8b 82 1c 16 00 00 85 c0 74 2b 8b 82 f8 15 00 00 <83> f8 02 75 20 48 8b 8a 00 16 00 00 8b 92 fc 15 00 00 48 8b 01 48 RSP: 0018:ffffc900037b7a08 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000004000 RCX: ffffffff843bbd87 RDX: ffff88805e85bc00 RSI: ffffffff843bbfb8 RDI: 0000000000000003 RBP: 1ffff920006f6f43 R08: 0000000000000003 R09: 0000000000004000 R10: 0000000000004000 R11: 0000000000000001 R12: ffff888011f64b18 R13: 0000000000000081 R14: 0000000000000001 R15: ffffc900037b7a38 file_mask_to_av security/selinux/hooks.c:1968 [inline] file_mask_to_av security/selinux/hooks.c:1952 [inline] selinux_inode_permission+0x418/0x590 security/selinux/hooks.c:3114 security_inode_permission+0xbb/0x120 security/security.c:2216 inode_permission fs/namei.c:536 [inline] inode_permission+0x17a/0x5f0 fs/namei.c:503 may_lookup fs/namei.c:1718 [inline] link_path_walk.part.0.constprop.0+0x226/0xcd0 fs/namei.c:2273 link_path_walk fs/namei.c:2255 [inline] path_lookupat+0x93/0x770 fs/namei.c:2492 filename_lookup+0x1e5/0x5b0 fs/namei.c:2522 user_path_at_empty+0x42/0x60 fs/namei.c:2929 user_path_at include/linux/namei.h:58 [inline] ksys_umount fs/namespace.c:1916 [inline] __do_sys_umount fs/namespace.c:1924 [inline] __se_sys_umount fs/namespace.c:1922 [inline] __x64_sys_umount+0x10e/0x1a0 fs/namespace.c:1922 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb55927e1d7 RSP: 002b:00007ffc4db62cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb55927e1d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc4db62db0 RBP: 00007ffc4db62db0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc4db63ea0 R13: 00007fb5592d9636 R14: 000055556bfa8430 R15: 0000000000000017 rcu: rcu_preempt kthread starved for 10528 jiffies! g26205 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:27200 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2000 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2202 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 7259 Comm: syz-executor.4 Not tainted 6.10.0-rc3-syzkaller-00022-gcea2a26553ac #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:__local_bh_enable_ip+0xac/0x120 kernel/softirq.c:389 Code: 1d b1 de b1 7e 65 8b 05 aa de b1 7e a9 00 ff ff 00 74 4d bf 01 00 00 00 e8 61 8f 0b 00 e8 dc 3b 43 00 fb 65 8b 05 8c de b1 7e <85> c0 74 52 5b 5d c3 cc cc cc cc 65 8b 05 8e 8d b0 7e 85 c0 75 9e RSP: 0018:ffffc90003447af0 EFLAGS: 00000202 RAX: 0000000080000000 RBX: 00000000fffffe01 RCX: 1ffffffff1fc8549 RDX: 0000000000000000 RSI: ffffffff8b2caf60 RDI: ffffffff8b900300 RBP: ffffffff81335d8f R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8fe46cd7 R11: 0000000000000000 R12: 00007f06eda7fd80 R13: 0000000000000001 R14: 0000000000000007 R15: ffff88805a1c8000 FS: 00007f06eda806c0(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f06eda7ff00 CR3: 000000005b776000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:80 [inline] restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:331 [inline] __fpu_restore_sig+0x634/0x1430 arch/x86/kernel/fpu/signal.c:359 fpu__restore_sig+0x102/0x180 arch/x86/kernel/fpu/signal.c:493 restore_sigcontext+0x4ca/0x6a0 arch/x86/kernel/signal_64.c:95 __do_sys_rt_sigreturn+0x138/0x230 arch/x86/kernel/signal_64.c:263 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f06ecc7cea7 Code: 14 25 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 RSP: 002b:00007f06eda80178 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f06ecdb3f88 RCX: 00007f06ecc7cea9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f06ecdb3f88 RBP: 00007f06ecdb3f80 R08: 00007f06eda806c0 R09: 00007f06eda806c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f06ecdb3f8c R13: 000000000000000b R14: 00007ffdb86d7240 R15: 00007ffdb86d7328