============================= [ BUG: Invalid wait context ] syzkaller #0 Not tainted ----------------------------- syz.0.0/5317 is trying to lock: ffff888050c41bb0 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x1f4/0x9a0 arch/x86/kvm/xen.c:1822 other info that might help us debug this: context-{2:2} 3 locks held by syz.0.0/5317: #0: ffff88801c2da450 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff88801c2da450 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #1: ffff888050fd38d0 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #1: ffff888050fd38d0 (&sb->s_type->i_mutex_key#15){+.+.}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3414 #2: ffff888050c42110 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #2: ffff888050c42110 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #2: ffff888050c42110 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1bc/0x9a0 arch/x86/kvm/xen.c:1820 stack backtrace: CPU: 0 UID: 0 PID: 5317 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 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+0xe39/0x2cf0 kernel/locking/lockdep.c:5187 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline] _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240 kvm_xen_set_evtchn_fast+0x1f4/0x9a0 arch/x86/kvm/xen.c:1822 xen_timer_callback+0x109/0x220 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x371/0xa10 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:stack_depot_save+0x4/0x10 lib/stackdepot.c:747 Code: 48 83 3d 3e d2 9b 15 00 75 c8 90 0f 0b 90 eb c2 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 01 00 00 00 e9 e2 f7 ff ff 66 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000f34f2d8 EFLAGS: 00000246 RAX: 000000000000000e RBX: ffff88803e8805f8 RCX: 542f2bbdb3aa6c00 RDX: 0000000000140cca RSI: 000000000000000e RDI: ffffc9000f34f320 RBP: ffffc9000f34f410 R08: ffffffff81d76566 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000 R13: 1ffff11007d100bf R14: ffffc9000f34f320 R15: 1ffff92001e69e60 save_stack+0x130/0x230 mm/page_owner.c:166 __set_page_owner+0x8d/0x4c0 mm/page_owner.c:341 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_pages_mpol+0x212/0x380 mm/mempolicy.c:2490 folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2509 shmem_alloc_folio mm/shmem.c:1917 [inline] shmem_alloc_and_add_folio+0x43e/0xf60 mm/shmem.c:1959 shmem_get_folio_gfp+0x5da/0x16d0 mm/shmem.c:2512 shmem_get_folio mm/shmem.c:2618 [inline] shmem_write_begin+0x16c/0x330 mm/shmem.c:3249 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4364 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3424 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f146115e90e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007f14620f0cb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f14620f16c0 RCX: 00007f146115e90e RDX: 0000000001000000 RSI: 00007f1455000000 RDI: 0000000000000006 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 00007f14620f0d9c R14: 00007f14620f0da0 R15: 00007f1455000000 ---------------- Code disassembly (best guess): 0: 48 83 3d 3e d2 9b 15 cmpq $0x0,0x159bd23e(%rip) # 0x159bd246 7: 00 8: 75 c8 jne 0xffffffd2 a: 90 nop b: 0f 0b ud2 d: 90 nop e: eb c2 jmp 0xffffffd2 10: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: 90 nop 23: 90 nop 24: 90 nop 25: 90 nop 26: f3 0f 1e fa endbr64 * 2a: b9 01 00 00 00 mov $0x1,%ecx <-- trapping instruction 2f: e9 e2 f7 ff ff jmp 0xfffff816 34: 66 90 xchg %ax,%ax 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop