==================================================================
BUG: KCSAN: data-race in detach_buf_split / virtqueue_add

read to 0xffff888101bdde2c of 4 bytes by task 7071 on cpu 0:
 virtqueue_add_split drivers/virtio/virtio_ring.c:575 [inline]
 virtqueue_add+0x75a/0x20e0 drivers/virtio/virtio_ring.c:2133
 virtqueue_add_inbuf+0x53/0x80 drivers/virtio/virtio_ring.c:2212
 request_entropy drivers/char/hw_random/virtio-rng.c:61 [inline]
 copy_data drivers/char/hw_random/virtio-rng.c:74 [inline]
 virtio_read+0x1c5/0x3f0 drivers/char/hw_random/virtio-rng.c:92
 rng_get_data drivers/char/hw_random/core.c:197 [inline]
 rng_dev_read+0x1a7/0x5e0 drivers/char/hw_random/core.c:234
 vfs_read+0x19e/0x580 fs/read_write.c:468
 ksys_read+0xeb/0x1a0 fs/read_write.c:613
 __do_sys_read fs/read_write.c:623 [inline]
 __se_sys_read fs/read_write.c:621 [inline]
 __x64_sys_read+0x42/0x50 fs/read_write.c:621
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read-write to 0xffff888101bdde2c of 4 bytes by interrupt on cpu 1:
 detach_buf_split+0x316/0x570 drivers/virtio/virtio_ring.c:760
 virtqueue_get_buf_ctx_split drivers/virtio/virtio_ring.c:835 [inline]
 virtqueue_get_buf_ctx+0x3c2/0x5b0 drivers/virtio/virtio_ring.c:2327
 virtqueue_get_buf+0x1f/0x30 drivers/virtio/virtio_ring.c:2333
 random_recv_done+0x4c/0x90 drivers/char/hw_random/virtio-rng.c:42
 vring_interrupt+0x150/0x170 drivers/virtio/virtio_ring.c:2501
 __handle_irq_event_percpu+0x91/0x490 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+0x167/0x590 kernel/irq/chip.c:819
 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
 handle_irq arch/x86/kernel/irq.c:231 [inline]
 __common_interrupt+0x3c/0xb0 arch/x86/kernel/irq.c:250
 common_interrupt+0x7a/0x90 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636
 get_next_corpse net/netfilter/nf_conntrack_core.c:2368 [inline]
 nf_ct_iterate_cleanup+0x219/0x3c0 net/netfilter/nf_conntrack_core.c:2422
 nf_ct_iterate_cleanup_net+0x8a/0xa0 net/netfilter/nf_conntrack_core.c:2443
 iterate_cleanup_work+0x66/0x120 net/netfilter/nf_nat_masquerade.c:87
 process_one_work+0x3e6/0x750 kernel/workqueue.c:2405
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2552
 kthread+0x1d7/0x210 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x00000100 -> 0x000000ff

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4115 Comm: kworker/1:19 Not tainted 6.4.0-rc6-syzkaller-00035-g15adb51c04cc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Workqueue: events iterate_cleanup_work
==================================================================
==================================================================
BUG: KCSAN: data-race in detach_buf_split / virtqueue_add

read to 0xffff888101bdde48 of 4 bytes by task 7083 on cpu 0:
 virtqueue_add_split drivers/virtio/virtio_ring.c:553 [inline]
 virtqueue_add+0x4b3/0x20e0 drivers/virtio/virtio_ring.c:2133
 virtqueue_add_inbuf+0x53/0x80 drivers/virtio/virtio_ring.c:2212
 request_entropy drivers/char/hw_random/virtio-rng.c:61 [inline]
 copy_data drivers/char/hw_random/virtio-rng.c:74 [inline]
 virtio_read+0x1c5/0x3f0 drivers/char/hw_random/virtio-rng.c:92
 rng_get_data drivers/char/hw_random/core.c:197 [inline]
 rng_dev_read+0x1a7/0x5e0 drivers/char/hw_random/core.c:234
 vfs_read+0x19e/0x580 fs/read_write.c:468
 ksys_read+0xeb/0x1a0 fs/read_write.c:613
 __do_sys_read fs/read_write.c:623 [inline]
 __se_sys_read fs/read_write.c:621 [inline]
 __x64_sys_read+0x42/0x50 fs/read_write.c:621
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read-write to 0xffff888101bdde48 of 4 bytes by interrupt on cpu 1:
 detach_buf_split+0x2fc/0x570 drivers/virtio/virtio_ring.c:757
 virtqueue_get_buf_ctx_split drivers/virtio/virtio_ring.c:835 [inline]
 virtqueue_get_buf_ctx+0x3c2/0x5b0 drivers/virtio/virtio_ring.c:2327
 virtqueue_get_buf+0x1f/0x30 drivers/virtio/virtio_ring.c:2333
 random_recv_done+0x4c/0x90 drivers/char/hw_random/virtio-rng.c:42
 vring_interrupt+0x150/0x170 drivers/virtio/virtio_ring.c:2501
 __handle_irq_event_percpu+0x91/0x490 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+0x167/0x590 kernel/irq/chip.c:819
 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
 handle_irq arch/x86/kernel/irq.c:231 [inline]
 __common_interrupt+0x3c/0xb0 arch/x86/kernel/irq.c:250
 common_interrupt+0x7a/0x90 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636
 get_next_corpse net/netfilter/nf_conntrack_core.c:2369 [inline]
 nf_ct_iterate_cleanup+0x8b/0x3c0 net/netfilter/nf_conntrack_core.c:2422
 nf_ct_iterate_cleanup_net+0x8a/0xa0 net/netfilter/nf_conntrack_core.c:2443
 iterate_cleanup_work+0x66/0x120 net/netfilter/nf_nat_masquerade.c:87
 process_one_work+0x3e6/0x750 kernel/workqueue.c:2405
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2552
 kthread+0x1d7/0x210 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3166 Comm: kworker/1:5 Not tainted 6.4.0-rc6-syzkaller-00035-g15adb51c04cc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Workqueue: events iterate_cleanup_work
==================================================================