=============================
[ BUG: Invalid wait context ]
syzkaller #0 Not tainted
-----------------------------
syz.3.576/8435 is trying to lock:
ffff88805e1a5430 (&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}
10 locks held by syz.3.576/8435:
#0: ffff88807f9c7418 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1675 [inline]
#0: ffff88807f9c7418 (sk_lock-AF_INET){+.+.}-{0:0}, at: sctp_sendmsg+0xb97/0x2810 net/sctp/socket.c:1970
#1: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#1: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#1: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: __ip_queue_xmit+0x5d/0x1c30 net/ipv4/ip_output.c:477
#2: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#2: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450 net/ipv4/ip_output.c:433
#3: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#3: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#3: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x452/0x1160 net/ipv4/ip_output.c:230
#4: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: local_lock_acquire include/linux/local_lock_internal.h:41 [inline]
#4: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: process_backlog+0x2d5/0x14f0 net/core/dev.c:6533
#5: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#5: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#5: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: ip_local_deliver_finish+0x2ae/0x6f0 net/ipv4/ip_input.c:238
#6: ffff88807f9c6218 (slock-AF_INET){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
#6: ffff88807f9c6218 (slock-AF_INET){+.-.}-{3:3}, at: sctp_rcv+0xffd/0x1820 net/sctp/input.c:218
#7: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#7: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#7: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: ip_route_output_key_hash+0xc1/0x280 net/ipv4/route.c:2699
#8: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#8: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#8: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1169 [inline]
#8: ffffffff8e33d260 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x2390 arch/x86/kernel/unwind_orc.c:479
#9: ffff88805e1a5980 (&kvm->srcu){.?.?}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#9: ffff88805e1a5980 (&kvm->srcu){.?.?}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#9: ffff88805e1a5980 (&kvm->srcu){.?.?}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1c3/0x9b0 arch/x86/kvm/xen.c:1818
stack backtrace:
CPU: 1 UID: 0 PID: 8435 Comm: syz.3.576 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline]
RIP: 0010:rcu_is_watching+0x9/0xb0 kernel/rcu/tree.c:750
Code: 5d 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 <65> ff 05 10 1d 1d 11 e8 db 87 de 09 89 c3 83 f8 08 73 65 49 bf 00
RSP: 0018:ffffc90000a074f0 EFLAGS: 00000297
RAX: 0000000000000001 RBX: ffffffff90e34401 RCX: 9c380f8cb8944b00
RDX: ffffc90000a07601 RSI: ffffffff8173bd25 RDI: ffffffff8e33d260
RBP: dffffc0000000000 R08: ffffc900053b7220 R09: 0000000000000000
R10: ffffc90000a07698 R11: fffff52000140ed5 R12: ffffc900053b7230
R13: ffffffff8173bd25 R14: ffffffff8e33d260 R15: ffffffff8173bd25
trace_lock_release include/trace/events/lock.h:69 [inline]
lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5879
rcu_lock_release include/linux/rcupdate.h:341 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1169 [inline]
unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:342 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4945 [inline]
slab_alloc_node mm/slub.c:5244 [inline]
kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5251
dst_alloc+0x105/0x170 net/core/dst.c:89
rt_dst_alloc net/ipv4/route.c:1646 [inline]
__mkroute_output net/ipv4/route.c:2650 [inline]
ip_route_output_key_hash_rcu+0x1560/0x23e0 net/ipv4/route.c:2870
ip_route_output_key_hash+0x174/0x280 net/ipv4/route.c:2700
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2927
ip_route_output_key include/net/route.h:179 [inline]
sctp_v4_get_dst+0x3c7/0x1200 net/sctp/protocol.c:455
sctp_transport_route+0x118/0x2f0 net/sctp/transport.c:457
sctp_assoc_add_peer+0x657/0x13b0 net/sctp/associola.c:663
sctp_process_param net/sctp/sm_make_chunk.c:2546 [inline]
sctp_process_init+0xe1e/0x2b60 net/sctp/sm_make_chunk.c:2366
sctp_sf_do_5_1D_ce+0x895/0x16f0 net/sctp/sm_statefuns.c:800
sctp_do_sm+0x1e7/0x5a20 net/sctp/sm_sideeffect.c:1172
sctp_endpoint_bh_rcv+0x591/0x7e0 net/sctp/endpointola.c:408
sctp_rcv+0x11c1/0x1820 net/sctp/input.c:243
ip_protocol_deliver_rcu+0x2e0/0x440 net/ipv4/ip_input.c:205
ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:239
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
NF_HOOK+0x30c/0x3a0 include/linux/netfilter.h:318
__netif_receive_skb_one_core net/core/dev.c:6072 [inline]
__netif_receive_skb+0x143/0x380 net/core/dev.c:6185
process_backlog+0x60e/0x14f0 net/core/dev.c:6537
__napi_poll+0xc7/0x360 net/core/dev.c:7587
napi_poll net/core/dev.c:7650 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7777
handle_softirqs+0x286/0x870 kernel/softirq.c:622
do_softirq+0xec/0x180 kernel/softirq.c:523
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450
local_bh_enable include/linux/bottom_half.h:33 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:910 [inline]
__dev_queue_xmit+0x1d79/0x3b50 net/core/dev.c:4784
dev_queue_xmit include/linux/netdevice.h:3368 [inline]
neigh_hh_output include/net/neighbour.h:531 [inline]
neigh_output include/net/neighbour.h:545 [inline]
ip_finish_output2+0xd03/0x1160 net/ipv4/ip_output.c:237
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip_output+0x29f/0x450 net/ipv4/ip_output.c:438
ip_local_out net/ipv4/ip_output.c:131 [inline]
__ip_queue_xmit+0x118d/0x1c30 net/ipv4/ip_output.c:534
sctp_packet_transmit+0x2581/0x2bb0 net/sctp/output.c:653
sctp_outq_flush_transports net/sctp/outqueue.c:1173 [inline]
sctp_outq_flush+0xecb/0x3140 net/sctp/outqueue.c:1221
sctp_cmd_interpreter net/sctp/sm_sideeffect.c:-1 [inline]
sctp_side_effects net/sctp/sm_sideeffect.c:1204 [inline]
sctp_do_sm+0x5332/0x5a20 net/sctp/sm_sideeffect.c:1175
sctp_assoc_bh_rcv+0x3f2/0x630 net/sctp/associola.c:1034
sctp_backlog_rcv+0x167/0x3f0 net/sctp/input.c:331
sk_backlog_rcv include/net/sock.h:1158 [inline]
__release_sock+0x297/0x3a0 net/core/sock.c:3180
release_sock+0x5f/0x1f0 net/core/sock.c:3735
sctp_sendmsg+0x1b72/0x2810 net/sctp/socket.c:2036
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x19c/0x270 net/socket.c:729
__sys_sendto+0x3bd/0x520 net/socket.c:2231
__do_sys_sendto net/socket.c:2238 [inline]
__se_sys_sendto net/socket.c:2234 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2234
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: 0033:0x7f890f78eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8910677038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f890f9e6180 RCX: 00007f890f78eec9
RDX: 000000000001a000 RSI: 00002000000000c0 RDI: 000000000000000a
RBP: 00007f890f811f91 R08: 0000200000000280 R09: 0000000000000010
R10: 00000000000000c1 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f890f9e6218 R14: 00007f890f9e6180 R15: 00007ffe0be22198
hrtimer: interrupt took 1429760020 ns
----------------
Code disassembly (best guess):
0: 5d pop %rbp
1: 03 eb add %ebx,%ebp
3: cc int3
4: 66 66 66 66 2e 0f 1f data16 data16 data16 cs nopw 0x0(%rax,%rax,1)
b: 84 00 00 00 00 00
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
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: f3 0f 1e fa endbr64
25: 41 57 push %r15
27: 41 56 push %r14
29: 53 push %rbx
* 2a: 65 ff 05 10 1d 1d 11 incl %gs:0x111d1d10(%rip) # 0x111d1d41 <-- trapping instruction
31: e8 db 87 de 09 call 0x9de8811
36: 89 c3 mov %eax,%ebx
38: 83 f8 08 cmp $0x8,%eax
3b: 73 65 jae 0xa2
3d: 49 rex.WB
3e: bf .byte 0xbf