Hello, syzbot found the following issue on: HEAD commit: 2faac9a98f01 Merge tag 'keys-fixes-20230321' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1113f21cc80000 kernel config: https://syzkaller.appspot.com/x/.config?x=3eb0bb0ae89a5345 dashboard link: https://syzkaller.appspot.com/bug?extid=726dc8c62c3536431ceb compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/571c9c5a3db2/disk-2faac9a9.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a051e3d7c495/vmlinux-2faac9a9.xz kernel image: https://storage.googleapis.com/syzbot-assets/ff5ec0d6e37d/bzImage-2faac9a9.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+726dc8c62c3536431ceb@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KCSAN: data-race in random_recv_done / virtio_read read to 0xffff8881019054ec of 4 bytes by task 14079 on cpu 0: copy_data drivers/char/hw_random/virtio-rng.c:70 [inline] virtio_read+0xc3/0x3f0 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+0x192/0x560 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 write to 0xffff8881019054ec of 4 bytes by interrupt on cpu 1: random_recv_done+0x62/0x90 drivers/char/hw_random/virtio-rng.c:45 vring_interrupt+0x150/0x170 drivers/virtio/virtio_ring.c:2491 __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+0x17f/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+0x64/0x100 arch/x86/kernel/irq.c:250 common_interrupt+0x49/0xc0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 value changed: 0x00000000 -> 0x00000040 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 14077 Comm: syz-executor.2 Not tainted 6.3.0-rc3-syzkaller-00016-g2faac9a98f01 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 ================================================================== ================================================================== BUG: KCSAN: data-race in detach_buf_split / virtqueue_add read to 0xffff888101a76950 of 4 bytes by task 14131 on cpu 0: virtqueue_add_split drivers/virtio/virtio_ring.c:553 [inline] virtqueue_add+0x4b9/0x2130 drivers/virtio/virtio_ring.c:2117 virtqueue_add_inbuf+0x53/0x80 drivers/virtio/virtio_ring.c:2196 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+0x192/0x560 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 0xffff888101a76950 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+0x3c8/0x5c0 drivers/virtio/virtio_ring.c:2311 virtqueue_get_buf+0x1f/0x30 drivers/virtio/virtio_ring.c:2317 random_recv_done+0x4c/0x90 drivers/char/hw_random/virtio-rng.c:42 vring_interrupt+0x150/0x170 drivers/virtio/virtio_ring.c:2491 __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+0x17f/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+0x64/0x100 arch/x86/kernel/irq.c:250 common_interrupt+0x9e/0xc0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:636 xas_find+0x10a/0x3f0 find_get_entry mm/filemap.c:2008 [inline] filemap_get_folios+0xa4/0x3f0 mm/filemap.c:2174 mpage_map_and_submit_buffers fs/ext4/inode.c:2358 [inline] mpage_map_and_submit_extent fs/ext4/inode.c:2513 [inline] ext4_do_writepages+0x1017/0x2140 fs/ext4/inode.c:2876 ext4_writepages+0x127/0x250 fs/ext4/inode.c:2964 do_writepages+0x1c5/0x340 mm/page-writeback.c:2551 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:390 __filemap_fdatawrite_range mm/filemap.c:423 [inline] __filemap_fdatawrite mm/filemap.c:429 [inline] filemap_flush+0x95/0xc0 mm/filemap.c:456 ext4_alloc_da_blocks+0x50/0x130 fs/ext4/inode.c:3218 ext4_release_file+0x5f/0x1c0 fs/ext4/file.c:158 __fput+0x245/0x570 fs/file_table.c:321 ____fput+0x15/0x20 fs/file_table.c:349 task_work_run+0x123/0x160 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x600/0x1710 kernel/exit.c:869 do_group_exit+0x101/0x150 kernel/exit.c:1019 get_signal+0xea9/0xfe0 kernel/signal.c:2859 arch_do_signal_or_restart+0x89/0x2b0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop+0x6d/0xe0 kernel/entry/common.c:168 exit_to_user_mode_prepare+0x6a/0xa0 kernel/entry/common.c:203 irqentry_exit_to_user_mode+0x9/0x20 kernel/entry/common.c:309 irqentry_exit+0x12/0x40 kernel/entry/common.c:412 exc_general_protection+0x339/0x4c0 arch/x86/kernel/traps.c:728 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:564 value changed: 0x00000001 -> 0x00000000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 14098 Comm: syz-executor.1 Not tainted 6.3.0-rc3-syzkaller-00016-g2faac9a98f01 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 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