syzbot


KCSAN: data-race in virtqueue_disable_cb / vring_interrupt (4)

Status: upstream: reported on 2024/09/12 08:11
Subsystems: virt
[Documentation on labels]
Reported-by: syzbot+8a02104389c2e0ef5049@syzkaller.appspotmail.com
First crash: 6d10h, last: 6d10h
Discussions (3)
Title Replies (including bot) Last reply
[PATCH v2] virtio_ring: tag event_triggered as racy for KCSAN 3 (3) 2024/09/13 03:29
[syzbot] [virt?] KCSAN: data-race in virtqueue_disable_cb / vring_interrupt (4) 6 (7) 2024/09/12 15:00
[PATCH] virtio_ring: tag event_triggered as racy for KCSAN 2 (2) 2024/09/12 14:50
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in virtqueue_disable_cb / vring_interrupt (2) virt 25 119d 282d 0/28 auto-obsoleted due to no activity on 2024/06/26 00:26
upstream KCSAN: data-race in virtqueue_disable_cb / vring_interrupt virt 130 390d 877d 0/28 auto-obsoleted due to no activity on 2023/09/29 09:42
upstream KCSAN: data-race in virtqueue_disable_cb / vring_interrupt (3) virt 2 46d 76d 0/28 auto-obsoleted due to no activity on 2024/09/06 16:53

Sample crash report:
==================================================================
BUG: KCSAN: data-race in virtqueue_disable_cb / vring_interrupt

write to 0xffff88810285ef52 of 1 bytes by interrupt on cpu 0:
 vring_interrupt+0x12b/0x180 drivers/virtio/virtio_ring.c:2591
 __handle_irq_event_percpu+0x95/0x490 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0x64/0xf0 kernel/irq/handle.c:210
 handle_edge_irq+0x16d/0x5b0 kernel/irq/chip.c:831
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq arch/x86/kernel/irq.c:247 [inline]
 call_irq_handler arch/x86/kernel/irq.c:259 [inline]
 __common_interrupt+0x58/0xe0 arch/x86/kernel/irq.c:285
 common_interrupt+0x7c/0x90 arch/x86/kernel/irq.c:278
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline]
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irq+0x2f/0x50 kernel/locking/spinlock.c:202
 process_one_work kernel/workqueue.c:3200 [inline]
 process_scheduled_works+0x43b/0x9a0 kernel/workqueue.c:3312
 worker_thread+0x526/0x6e0 kernel/workqueue.c:3389
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff88810285ef52 of 1 bytes by interrupt on cpu 1:
 virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:892 [inline]
 virtqueue_disable_cb+0x92/0x180 drivers/virtio/virtio_ring.c:2446
 start_xmit+0x14b/0x1260 drivers/net/virtio_net.c:3034
 __netdev_start_xmit include/linux/netdevice.h:4913 [inline]
 netdev_start_xmit include/linux/netdevice.h:4922 [inline]
 xmit_one net/core/dev.c:3580 [inline]
 dev_hard_start_xmit+0x119/0x3f0 net/core/dev.c:3596
 sch_direct_xmit+0x1b0/0x580 net/sched/sch_generic.c:343
 __dev_xmit_skb net/core/dev.c:3809 [inline]
 __dev_queue_xmit+0xf3d/0x1fe0 net/core/dev.c:4389
 dev_queue_xmit include/linux/netdevice.h:3105 [inline]
 neigh_hh_output include/net/neighbour.h:526 [inline]
 neigh_output include/net/neighbour.h:540 [inline]
 ip_finish_output2+0x73d/0x8b0 net/ipv4/ip_output.c:235
 ip_finish_output+0x11a/0x2a0 net/ipv4/ip_output.c:323
 NF_HOOK_COND include/linux/netfilter.h:303 [inline]
 ip_output+0xab/0x170 net/ipv4/ip_output.c:433
 dst_output include/net/dst.h:450 [inline]
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0xbcc/0xbf0 net/ipv4/ip_output.c:535
 ip_queue_xmit+0x38/0x50 net/ipv4/ip_output.c:549
 __tcp_transmit_skb+0x15b0/0x1970 net/ipv4/tcp_output.c:1466
 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline]
 tcp_write_xmit+0x1273/0x31c0 net/ipv4/tcp_output.c:2829
 __tcp_push_pending_frames+0x6a/0x1a0 net/ipv4/tcp_output.c:3014
 tcp_push_pending_frames include/net/tcp.h:2106 [inline]
 tcp_data_snd_check net/ipv4/tcp_input.c:5707 [inline]
 tcp_rcv_established+0xa12/0xef0 net/ipv4/tcp_input.c:6141
 tcp_v4_do_rcv+0x662/0x740 net/ipv4/tcp_ipv4.c:1911
 tcp_v4_rcv+0x1b25/0x1ee0 net/ipv4/tcp_ipv4.c:2346
 ip_protocol_deliver_rcu+0x370/0x720 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x17d/0x210 net/ipv4/ip_input.c:233
 NF_HOOK include/linux/netfilter.h:314 [inline]
 ip_local_deliver+0xec/0x1d0 net/ipv4/ip_input.c:254
 dst_input include/net/dst.h:460 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
 ip_sublist_rcv+0x55a/0x640 net/ipv4/ip_input.c:639
 ip_list_rcv+0x25e/0x290 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5704 [inline]
 __netif_receive_skb_list_core+0x4f0/0x520 net/core/dev.c:5752
 __netif_receive_skb_list net/core/dev.c:5804 [inline]
 netif_receive_skb_list_internal+0x4e4/0x660 net/core/dev.c:5896
 gro_normal_list include/net/gro.h:515 [inline]
 napi_complete_done+0x1cb/0x450 net/core/dev.c:6247
 virtqueue_napi_complete drivers/net/virtio_net.c:694 [inline]
 virtnet_poll+0x1b73/0x1fd0 drivers/net/virtio_net.c:2826
 __napi_poll+0x63/0x3c0 net/core/dev.c:6772
 napi_poll net/core/dev.c:6841 [inline]
 net_rx_action+0x3a1/0x7f0 net/core/dev.c:6963
 handle_softirqs+0xc3/0x280 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu kernel/softirq.c:637 [inline]
 irq_exit_rcu+0x3e/0x90 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0x37/0x80 arch/x86/kernel/apic/apic.c:1043
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 31238 Comm: syz.2.3839 Not tainted 6.11.0-rc7-syzkaller-00021-g7c6a3a65ace7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/12 03:07 upstream 7c6a3a65ace7 d94c83d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in virtqueue_disable_cb / vring_interrupt
* Struck through repros no longer work on HEAD.