On Mon, Sep 30, 2019 at 08:29:07PM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 014077b5 DO-NOT-SUBMIT: usb-fuzzer: main usb gadget fuzzer.. > git tree: https://github.com/google/kmsan.git master > console output: https://syzkaller.appspot.com/x/log.txt?x=108b5826600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=f03c659d0830ab8d > dashboard link: https://syzkaller.appspot.com/bug?extid=224d4aba0201decca39c > compiler: clang version 9.0.0 (/home/glider/llvm/clang > 80fee25776c2fb61e74c1ecb1a523375c2500b69) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15abd5c1600000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=168e3a3a600000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+224d4aba0201decca39c@xxxxxxxxxxxxxxxxxxxxxxxxx > > usb 1-1: USB disconnect, device number 23 > ================================================================== > BUG: KMSAN: uninit-value in adu_disconnect+0x302/0x360 > drivers/usb/misc/adutux.c:774 > CPU: 0 PID: 3372 Comm: kworker/0:2 Not tainted 5.3.0-rc7+ #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Workqueue: usb_hub_wq hub_event > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x191/0x1f0 lib/dump_stack.c:113 > kmsan_report+0x162/0x2d0 mm/kmsan/kmsan_report.c:109 > __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:294 > adu_disconnect+0x302/0x360 drivers/usb/misc/adutux.c:774 > usb_unbind_interface+0x3a2/0xdd0 drivers/usb/core/driver.c:423 > __device_release_driver drivers/base/dd.c:1120 [inline] > device_release_driver_internal+0x911/0xd20 drivers/base/dd.c:1151 > device_release_driver+0x4b/0x60 drivers/base/dd.c:1174 > bus_remove_device+0x4bf/0x670 drivers/base/bus.c:556 > device_del+0xcd5/0x1d10 drivers/base/core.c:2339 > usb_disable_device+0x567/0x1150 drivers/usb/core/message.c:1241 > usb_disconnect+0x51e/0xd60 drivers/usb/core/hub.c:2199 > hub_port_connect drivers/usb/core/hub.c:4949 [inline] > hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] > port_event drivers/usb/core/hub.c:5359 [inline] > hub_event+0x3fd0/0x72f0 drivers/usb/core/hub.c:5441 > process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269 > worker_thread+0x111b/0x2460 kernel/workqueue.c:2415 > kthread+0x4b5/0x4f0 kernel/kthread.c:256 > ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355 > > Uninit was created at: > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:189 [inline] > kmsan_internal_poison_shadow+0x58/0xb0 mm/kmsan/kmsan.c:148 > kmsan_slab_free+0x8d/0x100 mm/kmsan/kmsan_hooks.c:195 > slab_free_freelist_hook mm/slub.c:1472 [inline] > slab_free mm/slub.c:3038 [inline] > kfree+0x4c1/0x2db0 mm/slub.c:3980 > adu_delete drivers/usb/misc/adutux.c:151 [inline] > adu_release+0x95f/0xa50 drivers/usb/misc/adutux.c:332 > __fput+0x4c9/0xba0 fs/file_table.c:280 > ____fput+0x37/0x40 fs/file_table.c:313 > task_work_run+0x22e/0x2a0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop arch/x86/entry/common.c:163 [inline] > prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:194 > syscall_return_slowpath+0x90/0x610 arch/x86/entry/common.c:274 > do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:300 > entry_SYSCALL_64_after_hwframe+0x63/0xe7 > ================================================================== Likely another manifestation of #sys dup: KASAN: use-after-free Read in adu_disconnect Fix posted here https://lkml.kernel.org/r/20190925092913.8608-1-johan@xxxxxxxxxx Johan
