============================= [ BUG: Invalid wait context ] syzkaller #0 Not tainted ----------------------------- udevd/6460 is trying to lock: ffff888026f2d430 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x1fb/0x9b0 arch/x86/kvm/xen.c:1820 other info that might help us debug this: context-{2:2} 2 locks held by udevd/6460: #0: ffffffff8e13d400 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d400 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2599 [inline] #0: ffffffff8e13d400 (rcu_callback){....}-{0:0}, at: rcu_core+0xc37/0x1770 kernel/rcu/tree.c:2861 #1: ffff888026f2d980 (&kvm->srcu){.?.?}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #1: ffff888026f2d980 (&kvm->srcu){.?.?}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #1: ffff888026f2d980 (&kvm->srcu){.?.?}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1c3/0x9b0 arch/x86/kvm/xen.c:1818 stack backtrace: CPU: 0 UID: 0 PID: 6460 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4830 [inline] check_wait_context kernel/locking/lockdep.c:4902 [inline] __lock_acquire+0xbcb/0xd20 kernel/locking/lockdep.c:5187 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236 kvm_xen_set_evtchn_fast+0x1fb/0x9b0 arch/x86/kvm/xen.c:1820 xen_timer_callback+0x109/0x220 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x4e0/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:98 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline] RIP: 0010:kasan_check_range+0x9f/0x2c0 mm/kasan/generic.c:200 Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 de 01 00 00 49 ff c3 48 ff c3 75 ee e9 21 01 00 00 44 89 dd RSP: 0018:ffffc90000007ac8 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff82176f2c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8f9e1170 RBP: ffffea0001177bc8 R08: ffffffff8f9e1177 R09: 1ffffffff1f3c22e R10: dffffc0000000000 R11: fffffbfff1f3c22e R12: 0000000000000001 R13: 1ffffd400022ef79 R14: fffffbfff1f3c22f R15: 1ffffffff1f3c22e 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:646 [inline] cpu_online include/linux/cpumask.h:1205 [inline] trace_mm_page_free+0x2c/0x140 include/trace/events/kmem.h:139 free_pages_prepare mm/page_alloc.c:1315 [inline] __free_frozen_pages+0x160/0xd30 mm/page_alloc.c:2906 __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:290 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x286/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__might_sleep+0x0/0x100 kernel/sched/core.c:8841 Code: 80 e1 07 38 c1 0f 8c 3c ff ff ff 48 89 df e8 07 1f 94 00 e9 2f ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc RSP: 0018:ffffc9000ae07b40 EFLAGS: 00000246 RAX: ffffffff820d9623 RBX: ffff88802b585ac0 RCX: 0000000000000000 RDX: ffff88802b585ac0 RSI: 00000000000000a2 RDI: ffffffff8bbfca20 RBP: 00000000000000a2 R08: ffffc9000ae07c37 R09: 0000000000000000 R10: ffffc9000ae07c00 R11: fffff520015c0f87 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffffff8bbfca20 R15: 0000000000000000 __might_fault+0x77/0x130 mm/memory.c:7079 _inline_copy_from_user include/linux/uaccess.h:162 [inline] _copy_from_user+0x28/0xb0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] copy_msghdr_from_user net/socket.c:2560 [inline] recvmsg_copy_msghdr net/socket.c:2816 [inline] ___sys_recvmsg+0x12e/0x510 net/socket.c:2888 __sys_recvmsg net/socket.c:2925 [inline] __do_sys_recvmsg net/socket.c:2931 [inline] __se_sys_recvmsg net/socket.c:2928 [inline] __x64_sys_recvmsg+0x198/0x260 net/socket.c:2928 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f580a3cb407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff9e6ca0a0 EFLAGS: 00000202 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00007f580a33f880 RCX: 00007f580a3cb407 RDX: 0000000000000000 RSI: 00007fff9e6ca130 RDI: 000000000000000c RBP: 000055ffd4221910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055ffd43840c0 R13: 00007fff9e6ca1f0 R14: 00007fff9e6ca13c R15: 0000000000000000 ---------------- Code disassembly (best guess), 3 bytes skipped: 0: df 4d 8d fisttps -0x73(%rbp) 3: 34 19 xor $0x19,%al 5: 4d 89 f4 mov %r14,%r12 8: 4d 29 dc sub %r11,%r12 b: 49 83 fc 10 cmp $0x10,%r12 f: 7f 29 jg 0x3a 11: 4d 85 e4 test %r12,%r12 14: 0f 84 41 01 00 00 je 0x15b 1a: 4c 89 cb mov %r9,%rbx 1d: 48 f7 d3 not %rbx 20: 4c 01 fb add %r15,%rbx 23: 41 80 3b 00 cmpb $0x0,(%r11) * 27: 0f 85 de 01 00 00 jne 0x20b <-- trapping instruction 2d: 49 ff c3 inc %r11 30: 48 ff c3 inc %rbx 33: 75 ee jne 0x23 35: e9 21 01 00 00 jmp 0x15b 3a: 44 89 dd mov %r11d,%ebp