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BUG: KCSAN: data-race in random_recv_done / virtio_read

write to 0xffff88810147f8cc of 4 bytes by interrupt on cpu 1:
 random_recv_done+0x58/0x80 drivers/char/hw_random/virtio-rng.c:45
 vring_interrupt+0x14c/0x170 drivers/virtio/virtio_ring.c:2462
 __handle_irq_event_percpu+0x92/0x400 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0x60/0xf0 kernel/irq/handle.c:210
 handle_edge_irq+0x17e/0x5a0 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+0x60/0x100 arch/x86/kernel/irq.c:250
 common_interrupt+0x9a/0xc0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x22/0x40
 folio_clear_dirty_for_io+0x357/0x470
 clear_page_dirty_for_io+0x3b/0xe0 mm/folio-compat.c:74
 mpage_submit_page fs/ext4/inode.c:2094 [inline]
 mpage_map_and_submit_buffers fs/ext4/inode.c:2359 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2498 [inline]
 ext4_writepages+0xfc8/0x1cf0 fs/ext4/inode.c:2827
 do_writepages+0x1db/0x350 mm/page-writeback.c:2468
 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 file_write_and_wait_range+0xd6/0x170 mm/filemap.c:773
 ext4_sync_file+0x105/0x6d0 fs/ext4/fsync.c:151
 vfs_fsync_range+0x107/0x120 fs/sync.c:188
 generic_write_sync include/linux/fs.h:2869 [inline]
 ext4_buffered_write_iter+0x398/0x3e0 fs/ext4/file.c:277
 ext4_file_write_iter+0x2e3/0x1210
 do_iter_write+0x494/0x750 fs/read_write.c:855
 vfs_iter_write+0x4c/0x70 fs/read_write.c:896
 iter_file_splice_write+0x44a/0x7c0 fs/splice.c:686
 do_splice_from fs/splice.c:764 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:931
 splice_direct_to_actor+0x305/0x620 fs/splice.c:886
 do_splice_direct+0xfb/0x180 fs/splice.c:974
 do_sendfile+0x3bf/0x910 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1311 [inline]
 __se_sys_sendfile64 fs/read_write.c:1303 [inline]
 __x64_sys_sendfile64+0xb9/0x150 fs/read_write.c:1303
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

write to 0xffff88810147f8cc of 4 bytes by task 29550 on cpu 0:
 request_entropy drivers/char/hw_random/virtio-rng.c:56 [inline]
 copy_data drivers/char/hw_random/virtio-rng.c:74 [inline]
 virtio_read+0x190/0x430 drivers/char/hw_random/virtio-rng.c:92
 rng_get_data drivers/char/hw_random/core.c:191 [inline]
 rng_dev_read+0x1b4/0x630 drivers/char/hw_random/core.c:228
 do_iter_read+0x2d5/0x760 fs/read_write.c:792
 vfs_readv fs/read_write.c:910 [inline]
 do_preadv+0x159/0x230 fs/read_write.c:1002
 __do_sys_preadv fs/read_write.c:1052 [inline]
 __se_sys_preadv fs/read_write.c:1047 [inline]
 __x64_sys_preadv+0x54/0x60 fs/read_write.c:1047
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000040 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 29550 Comm: syz-executor.4 Not tainted 6.0.0-rc2-syzkaller-00248-ge022620b5d05-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
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