Hello, syzbot found the following issue on: HEAD commit: 3b68086599f8 Merge tag 'sched_urgent_for_v6.9_rc5' of git:.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=164f8bf7180000 kernel config: https://syzkaller.appspot.com/x/.config?x=f47e5e015c177e57 dashboard link: https://syzkaller.appspot.com/bug?extid=de026b20f56e1598e760 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1775971b180000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1290b320980000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/eaff65771f64/disk-3b680865.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/426ae4806417/vmlinux-3b680865.xz kernel image: https://storage.googleapis.com/syzbot-assets/e0e9686bbff2/bzImage-3b680865.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+de026b20f56e1598e760@xxxxxxxxxxxxxxxxxxxxxxxxx rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5096/1:b..l rcu: (detected by 1, t=10502 jiffies, g=5437, q=6 ncpus=2) task:syz-executor398 state:R running task stack:23960 pid:5096 tgid:5096 ppid:5090 flags:0x00000002 Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7068 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:check_region_inline mm/kasan/generic.c:171 [inline] RIP: 0010:kasan_check_range+0xe/0x290 mm/kasan/generic.c:189 Code: 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 41 57 41 56 41 54 53 b0 01 <48> 85 f6 0f 84 a0 01 00 00 4c 8d 04 37 49 39 f8 0f 82 56 02 00 00 RSP: 0018:ffffc90003e7f370 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81727ab4 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fa7b6a8 RBP: ffffc90003e7f4e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: ffff888029e00000 R12: 1ffff920007cfe7c R13: dffffc0000000000 R14: 0000000000000000 R15: 00007f1d974c829a instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:505 [inline] cpu_online include/linux/cpumask.h:1120 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xd4/0x550 kernel/locking/lockdep.c:5725 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] is_bpf_text_address+0x42/0x2b0 kernel/bpf/core.c:767 kernel_text_address+0xa7/0xe0 kernel/extable.c:125 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x125/0x1b0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3966 [inline] __kmalloc+0x233/0x4a0 mm/slub.c:3979 kmalloc include/linux/slab.h:632 [inline] kzalloc include/linux/slab.h:749 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80 tomoyo_mount_acl security/tomoyo/mount.c:97 [inline] tomoyo_mount_permission+0x356/0xb80 security/tomoyo/mount.c:237 security_sb_mount+0x8f/0xd0 security/security.c:1460 path_mount+0xb9/0xfb0 fs/namespace.c:3621 do_mount fs/namespace.c:3692 [inline] __do_sys_mount fs/namespace.c:3898 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3875 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1d974c829a RSP: 002b:00007ffd54ae8348 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f1d9751e043 RCX: 00007f1d974c829a RDX: 00007f1d9751e051 RSI: 00007f1d9751e043 RDI: 00007f1d9751e051 RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000055557430c370 R13: 0000000000000004 R14: 00007ffd54ae83c0 R15: 00007ffd54ae83b0 </TASK> rcu: rcu_preempt kthread starved for 10548 jiffies! g5437 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:26736 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5409 [inline] __schedule+0x1796/0x4a00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> 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: 5120 Comm: syz-executor398 Not tainted 6.9.0-rc4-syzkaller-00274-g3b68086599f8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:122 [inline] RIP: 0010:lock_release+0x125/0x9f0 kernel/locking/lockdep.c:5767 Code: 7e 85 c0 0f 85 23 05 00 00 65 48 8b 04 25 80 d3 03 00 48 89 44 24 18 48 8d 98 d4 0a 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 0f 85 d8 05 00 00 83 3b 00 0f 85 f1 04 00 00 4c 8d b4 24 b0 RSP: 0018:ffffc900040d7b20 EFLAGS: 00000803 RAX: 0000000000000000 RBX: ffff8880787fa8d4 RCX: ffffffff8172a120 RDX: 0000000000000000 RSI: ffffffff8c1eb140 RDI: ffffffff8c1eb100 RBP: ffffc900040d7c60 R08: ffffffff8fa7b6af R09: 1ffffffff1f4f6d5 R10: dffffc0000000000 R11: fffffbfff1f4f6d6 R12: 1ffff9200081af70 R13: ffffffff815cefdd R14: ffff888029df1718 R15: dffffc0000000000 FS: 000055557430c3c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1d974de4c0 CR3: 00000000773d4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:157 [inline] _raw_spin_unlock_irq+0x16/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x14dd/0x1740 kernel/signal.c:2914 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1d974c6e79 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 18 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:00007ffd54ae8348 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f1d974c6e79 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000055557430c370 R13: 0000000000000000 R14: 00007ffd54ae83c0 R15: 00007ffd54ae83b0 </TASK> sched: RT throttling activated --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
