Hello, syzbot found the following issue on: HEAD commit: d3d45f82 Merge tag 'pinctrl-v5.9-2' of git://git.kernel.or.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15781d8f900000 kernel config: https://syzkaller.appspot.com/x/.config?x=89ab6a0c48f30b49 dashboard link: https://syzkaller.appspot.com/bug?extid=bf1a360e305ee719e364 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16cbaa7d900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1364f367900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+bf1a360e305ee719e364@xxxxxxxxxxxxxxxxxxxxxxxxx vhci_hcd: stop threads vhci_hcd: release socket vhci_hcd: disconnect device ================================================================== BUG: KASAN: null-ptr-deref in instrument_atomic_write include/linux/instrumented.h:71 [inline] BUG: KASAN: null-ptr-deref in atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline] BUG: KASAN: null-ptr-deref in refcount_add include/linux/refcount.h:201 [inline] BUG: KASAN: null-ptr-deref in refcount_inc include/linux/refcount.h:241 [inline] BUG: KASAN: null-ptr-deref in get_task_struct include/linux/sched/task.h:104 [inline] BUG: KASAN: null-ptr-deref in kthread_stop+0x90/0x7e0 kernel/kthread.c:591 Write of size 4 at addr 000000000000001c by task kworker/u4:5/2519 CPU: 1 PID: 2519 Comm: kworker/u4:5 Not tainted 5.9.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usbip_event event_handler Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 __kasan_report mm/kasan/report.c:517 [inline] kasan_report.cold+0x5/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 instrument_atomic_write include/linux/instrumented.h:71 [inline] atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline] refcount_add include/linux/refcount.h:201 [inline] refcount_inc include/linux/refcount.h:241 [inline] get_task_struct include/linux/sched/task.h:104 [inline] kthread_stop+0x90/0x7e0 kernel/kthread.c:591 vhci_shutdown_connection+0x170/0x2a0 drivers/usb/usbip/vhci_hcd.c:1015 event_handler+0x1a5/0x450 drivers/usb/usbip/usbip_event.c:78 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 ================================================================== Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2519 Comm: kworker/u4:5 Tainted: G B 5.9.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usbip_event event_handler Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 panic+0x382/0x7fb kernel/panic.c:231 end_report+0x4d/0x53 mm/kasan/report.c:104 __kasan_report mm/kasan/report.c:520 [inline] kasan_report.cold+0xd/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x13d/0x180 mm/kasan/generic.c:192 instrument_atomic_write include/linux/instrumented.h:71 [inline] atomic_fetch_add_relaxed include/asm-generic/atomic-instrumented.h:142 [inline] refcount_add include/linux/refcount.h:201 [inline] refcount_inc include/linux/refcount.h:241 [inline] get_task_struct include/linux/sched/task.h:104 [inline] kthread_stop+0x90/0x7e0 kernel/kthread.c:591 vhci_shutdown_connection+0x170/0x2a0 drivers/usb/usbip/vhci_hcd.c:1015 event_handler+0x1a5/0x450 drivers/usb/usbip/usbip_event.c:78 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Kernel Offset: disabled Rebooting in 86400 seconds.. --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
