Hello, syzbot found the following issue on: HEAD commit: 3a7e02c040b1 minmax: avoid overly complicated constant exp.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=132e32bd980000 kernel config: https://syzkaller.appspot.com/x/.config?x=381b8eb3d35e3ad9 dashboard link: https://syzkaller.appspot.com/bug?extid=ff2407cef5068e202465 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/198814da854c/disk-3a7e02c0.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/868e99275bc0/vmlinux-3a7e02c0.xz kernel image: https://storage.googleapis.com/syzbot-assets/ce63033f3708/bzImage-3a7e02c0.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ff2407cef5068e202465@xxxxxxxxxxxxxxxxxxxxxxxxx rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9645/1:b..l P9626/1:b..l rcu: (detected by 0, t=10502 jiffies, g=53081, q=325 ncpus=2) task:syz-executor state:R running task stack:27168 pid:9626 tgid:9626 ppid:5216 flags:0x00004002 Call Trace: <TASK> context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851 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:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5727 Code: c1 05 3a 13 9a 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc90004647698 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920008c8ed5 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff8b4cc880 RDI: ffffffff8bb08c00 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff28c4cd8 R10: ffffffff946266c7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8ddb5220 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] page_ext_get+0x3a/0x310 mm/page_ext.c:535 __set_page_owner+0x96/0x560 mm/page_owner.c:322 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3438 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4696 alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2263 vm_area_alloc_pages mm/vmalloc.c:3584 [inline] __vmalloc_area_node mm/vmalloc.c:3660 [inline] __vmalloc_node_range_noprof+0xa6a/0x1520 mm/vmalloc.c:3841 vmalloc_user_noprof+0x6b/0x90 mm/vmalloc.c:3995 kcov_ioctl+0x4f/0x730 kernel/kcov.c:706 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:893 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: 0033:0x7fa518d76e9b RSP: 002b:00007ffd114116d0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007fa518d76e9b RDX: 0000000000100000 RSI: ffffffff80086301 RDI: 00000000000000d7 RBP: 00007fa518f05f40 R08: 00000000000000da R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000009 </TASK> task:syz-executor state:R running task stack:27088 pid:9645 tgid:9645 ppid:5216 flags:0x00000002 Call Trace: <TASK> context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] insert_page mm/memory.c:2077 [inline] vm_insert_page+0x45d/0x6d0 mm/memory.c:2226 kcov_mmap+0xda/0x150 kernel/kcov.c:496 call_mmap include/linux/fs.h:2129 [inline] mmap_region+0x757/0x2760 mm/mmap.c:2957 do_mmap+0xbfb/0xfb0 mm/mmap.c:1468 vm_mmap_pgoff+0x1ba/0x360 mm/util.c:588 ksys_mmap_pgoff+0x332/0x5d0 mm/mmap.c:1514 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:79 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:79 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: 0033:0x7f7bf4f772d3 RSP: 002b:00007ffc20fff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f7bf5106018 RCX: 00007f7bf4f772d3 RDX: 0000000000000003 RSI: 0000000000200000 RDI: 00007f7bf4601000 RBP: 00007f7bf4600000 R08: 00000000000000d8 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 000000000000000c R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000009 </TASK> rcu: rcu_preempt kthread starved for 10561 jiffies! g53081 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:27312 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236 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 </TASK> rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.10.0-syzkaller-12710-g3a7e02c040b1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 48 69 f2 74 48 8b 00 a8 08 75 0c 66 90 0f 00 2d b8 82 aa 00 fb f4 <fa> c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8da07d70 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8b115519 RDX: 0000000000000001 RSI: ffff88801a2cb800 RDI: ffff88801a2cb864 RBP: ffff88801a2cb864 R08: 0000000000000001 R09: ffffed1017246fe1 R10: ffff8880b9237f0b R11: 0000000000000000 R12: ffff88801c70a800 R13: ffffffff8e94eac0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1eebebf378 CR3: 000000006bb72000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> </IRQ> <TASK> acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:702 cpuidle_enter_state+0x85/0x500 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:388 cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x313/0x3f0 kernel/sched/idle.c:326 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:424 rest_init+0x16b/0x2b0 init/main.c:747 start_kernel+0x3df/0x4c0 init/main.c:1103 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488 common_startup_64+0x13e/0x148 </TASK> --- 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 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
