================================================================== BUG: KCSAN: data-race in random_recv_done / virtio_read write to 0xffff8881020294cc of 4 bytes by task 17355 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 vfs_read+0x1a1/0x6a0 fs/read_write.c:480 ksys_read+0xe8/0x1a0 fs/read_write.c:620 __do_sys_read fs/read_write.c:630 [inline] __se_sys_read fs/read_write.c:628 [inline] __x64_sys_read+0x3e/0x50 fs/read_write.c:628 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+0x44/0xae write to 0xffff8881020294cc of 4 bytes by interrupt on cpu 1: random_recv_done+0x58/0x80 drivers/char/hw_random/virtio-rng.c:45 vring_interrupt+0x15d/0x180 drivers/virtio/virtio_ring.c:2148 __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:817 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+0x1e/0x40 _find_next_bit+0x53/0x190 lib/find_bit.c:41 find_next_zero_bit include/linux/find.h:102 [inline] __sbitmap_get_word lib/sbitmap.c:145 [inline] sbitmap_find_bit_in_index lib/sbitmap.c:177 [inline] __sbitmap_get lib/sbitmap.c:206 [inline] sbitmap_get+0x1cf/0x470 lib/sbitmap.c:231 __sbitmap_queue_get+0x11/0x20 lib/sbitmap.c:504 __blk_mq_alloc_driver_tag block/blk-mq.c:1584 [inline] __blk_mq_get_driver_tag+0x1ad/0x460 block/blk-mq.c:1594 blk_mq_get_driver_tag block/blk-mq.h:283 [inline] __blk_mq_do_dispatch_sched block/blk-mq-sched.c:153 [inline] blk_mq_do_dispatch_sched+0x395/0x780 block/blk-mq-sched.c:187 __blk_mq_sched_dispatch_requests+0x1ca/0x270 blk_mq_sched_dispatch_requests+0x8f/0xf0 block/blk-mq-sched.c:339 __blk_mq_run_hw_queue+0x7e/0x100 block/blk-mq.c:1981 __blk_mq_delay_run_hw_queue+0x194/0x390 block/blk-mq.c:2058 blk_mq_run_hw_queue+0x180/0x310 block/blk-mq.c:2109 blk_mq_sched_insert_requests+0x1cb/0x2a0 block/blk-mq-sched.c:493 blk_mq_dispatch_plug_list+0x1e9/0x2c0 block/blk-mq.c:2604 blk_mq_flush_plug_list+0x2ea/0x340 block/blk-mq.c:2646 blk_add_rq_to_plug+0x13f/0x390 block/blk-mq.c:2707 blk_mq_submit_bio+0x91c/0xe40 block/blk-mq.c:2856 __submit_bio+0x130/0x330 block/blk-core.c:666 __submit_bio_noacct_mq block/blk-core.c:743 [inline] submit_bio_noacct_nocheck+0x425/0x480 block/blk-core.c:760 submit_bio_noacct+0x6c4/0x820 block/blk-core.c:867 submit_bio+0x139/0x150 ext4_io_submit fs/ext4/page-io.c:378 [inline] io_submit_add_bh fs/ext4/page-io.c:420 [inline] ext4_bio_write_page+0x43d/0x8a0 fs/ext4/page-io.c:546 mpage_submit_page fs/ext4/inode.c:2090 [inline] mpage_map_and_submit_buffers fs/ext4/inode.c:2336 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2475 [inline] ext4_writepages+0xe76/0x1970 fs/ext4/inode.c:2804 do_writepages+0x1db/0x350 mm/page-writeback.c:2352 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] __filemap_fdatawrite mm/filemap.c:427 [inline] filemap_flush+0x93/0xc0 mm/filemap.c:454 __ext4_ioctl fs/ext4/ioctl.c:1338 [inline] ext4_ioctl+0xcbf/0x20a0 fs/ext4/ioctl.c:1578 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856 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+0x44/0xae value changed: 0x00000040 -> 0x00000000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 17362 Comm: syz-executor.0 Tainted: G W 5.18.0-rc4-syzkaller-00036-gcf424ef014ac-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================