============================= [ BUG: Invalid wait context ] 6.16.0-syzkaller-00857-gced1b9e0392d #0 Not tainted ----------------------------- udevd/4739 is trying to lock: ffffc90001a07410 (&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} 4 locks held by udevd/4739: #0: ffff888011c8c428 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff88803e5f1ce8 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline] #1: ffff88803e5f1ce8 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: open_last_lookups fs/namei.c:3804 [inline] #1: ffff88803e5f1ce8 (&type->i_mutex_dir_key#5){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4043 #2: ffff888011c6d090 (&sbinfo->stat_lock){+.+.}-{2:2}, at: shmem_reserve_inode mm/shmem.c:354 [inline] #2: ffff888011c6d090 (&sbinfo->stat_lock){+.+.}-{2:2}, at: __shmem_get_inode mm/shmem.c:3045 [inline] #2: ffff888011c6d090 (&sbinfo->stat_lock){+.+.}-{2:2}, at: shmem_get_inode+0xb7/0xe90 mm/shmem.c:3123 #3: ffffc90001a07960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffffc90001a07960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffffc90001a07960 (&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: 4739 Comm: udevd Not tainted 6.16.0-syzkaller-00857-gced1b9e0392d #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4833 [inline] check_wait_context kernel/locking/lockdep.c:4905 [inline] __lock_acquire+0xbcb/0xd20 kernel/locking/lockdep.c:5190 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __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:1761 [inline] __hrtimer_run_queues+0x4dd/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 1b f4 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900028ef7f8 EFLAGS: 00000206 RAX: 965a8762f521d800 RBX: 0000000000000000 RCX: 965a8762f521d800 RDX: 0000000000000000 RSI: ffffffff8db8ccb9 RDI: ffffffff8be2df00 RBP: ffffffff82025d57 R08: 0000000000000000 R09: ffffffff82025d57 R10: dffffc0000000000 R11: ffffffff8202a990 R12: 0000000000000000 R13: ffff888011c6d090 R14: 0000000000000001 R15: 0000000000000246 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 shmem_reserve_inode mm/shmem.c:354 [inline] __shmem_get_inode mm/shmem.c:3045 [inline] shmem_get_inode+0xb7/0xe90 mm/shmem.c:3123 shmem_mknod+0x18c/0x3e0 mm/shmem.c:3844 lookup_open fs/namei.c:3708 [inline] open_last_lookups fs/namei.c:3807 [inline] path_openat+0x14f4/0x3830 fs/namei.c:4043 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6d214a7407 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:00007ffdc6dc0cd0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f6d21bba880 RCX: 00007f6d214a7407 RDX: 0000000000080141 RSI: 00005633d93c402e RDI: ffffffffffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001a4 R11: 0000000000000202 R12: 00000000ffffffff R13: 00000000ffffffff R14: ffffffffffffffff R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 9c pushf 5: 8f 44 24 30 pop 0x30(%rsp) 9: f7 44 24 30 00 02 00 testl $0x200,0x30(%rsp) 10: 00 11: 0f 85 cd 00 00 00 jne 0xe4 17: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp) 1e: 00 1f: 74 01 je 0x22 21: fb sti 22: 65 48 8b 05 1b f4 03 mov %gs:0x1103f41b(%rip),%rax # 0x1103f445 29: 11 * 2a: 48 3b 44 24 58 cmp 0x58(%rsp),%rax <-- trapping instruction 2f: 0f 85 f2 00 00 00 jne 0x127 35: 48 83 c4 60 add $0x60,%rsp 39: 5b pop %rbx 3a: 41 5c pop %r12 3c: 41 5d pop %r13 3e: 41 5e pop %r14