On Mon, Sep 23, 2019 at 4:31 PM syzbot <syzbot+ac438d7ad8171b0ecbbe@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: e0bd8d79 usb-fuzzer: main usb gadget fuzzer driver > git tree: https://github.com/google/kasan.git usb-fuzzer > console output: https://syzkaller.appspot.com/x/log.txt?x=14d4b6a1600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8847e5384a16f66a > dashboard link: https://syzkaller.appspot.com/bug?extid=ac438d7ad8171b0ecbbe > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+ac438d7ad8171b0ecbbe@xxxxxxxxxxxxxxxxxxxxxxxxx > > usb 4-1: usbvision_write_reg: failed: error -19 > usbvision_audio_off: can't write reg > usbvision_radio_close: Final disconnect > ================================================================== > BUG: KASAN: use-after-free in v4l2_release+0x2f1/0x390 > drivers/media/v4l2-core/v4l2-dev.c:459 > Read of size 4 at addr ffff8881c5c55228 by task v4l_id/16726 > > CPU: 0 PID: 16726 Comm: v4l_id Not tainted 5.3.0+ #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xca/0x13e lib/dump_stack.c:113 > print_address_description+0x6a/0x32c mm/kasan/report.c:351 > __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482 > kasan_report+0xe/0x12 mm/kasan/common.c:618 > v4l2_release+0x2f1/0x390 drivers/media/v4l2-core/v4l2-dev.c:459 > __fput+0x2d7/0x840 fs/file_table.c:280 > task_work_run+0x13f/0x1c0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:163 > prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] > syscall_return_slowpath arch/x86/entry/common.c:274 [inline] > do_syscall_64+0x45f/0x580 arch/x86/entry/common.c:300 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x7f26b3e742b0 > Code: 40 75 0b 31 c0 48 83 c4 08 e9 0c ff ff ff 48 8d 3d c5 32 08 00 e8 c0 > 07 02 00 83 3d 45 a3 2b 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff > ff 73 31 c3 48 83 ec 08 e8 ce 8a 01 00 48 89 04 24 > RSP: 002b:00007fff0e393978 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 > RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f26b3e742b0 > RDX: 00007f26b412adf0 RSI: 0000000000000001 RDI: 0000000000000003 > RBP: 0000000000000000 R08: 00007f26b412adf0 R09: 000000000000000a > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000400884 > R13: 00007fff0e393ad0 R14: 0000000000000000 R15: 0000000000000000 > > Allocated by task 2757: > save_stack+0x1b/0x80 mm/kasan/common.c:69 > set_track mm/kasan/common.c:77 [inline] > __kasan_kmalloc mm/kasan/common.c:493 [inline] > __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:466 > kmalloc include/linux/slab.h:552 [inline] > kzalloc include/linux/slab.h:748 [inline] > usbvision_alloc drivers/media/usb/usbvision/usbvision-video.c:1298 [inline] > usbvision_probe.cold+0x5c5/0x1f1f > drivers/media/usb/usbvision/usbvision-video.c:1452 > usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 > really_probe+0x281/0x6d0 drivers/base/dd.c:548 > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:721 > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 > bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 > __device_attach+0x217/0x360 drivers/base/dd.c:894 > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 > device_add+0xae6/0x16f0 drivers/base/core.c:2201 > usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 > generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 > usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 > really_probe+0x281/0x6d0 drivers/base/dd.c:548 > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:721 > __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828 > bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430 > __device_attach+0x217/0x360 drivers/base/dd.c:894 > bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490 > device_add+0xae6/0x16f0 drivers/base/core.c:2201 > usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536 > hub_port_connect drivers/usb/core/hub.c:5098 [inline] > hub_port_connect_change drivers/usb/core/hub.c:5213 [inline] > port_event drivers/usb/core/hub.c:5359 [inline] > hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441 > process_one_work+0x92b/0x1530 kernel/workqueue.c:2269 > worker_thread+0x96/0xe20 kernel/workqueue.c:2415 > kthread+0x318/0x420 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > Freed by task 16726: > save_stack+0x1b/0x80 mm/kasan/common.c:69 > set_track mm/kasan/common.c:77 [inline] > __kasan_slab_free+0x130/0x180 mm/kasan/common.c:455 > slab_free_hook mm/slub.c:1423 [inline] > slab_free_freelist_hook mm/slub.c:1474 [inline] > slab_free mm/slub.c:3016 [inline] > kfree+0xe4/0x2f0 mm/slub.c:3957 > usbvision_release+0x181/0x1c0 > drivers/media/usb/usbvision/usbvision-video.c:1347 > usbvision_radio_close.cold+0x6f/0x74 > drivers/media/usb/usbvision/usbvision-video.c:1113 > v4l2_release+0x2e7/0x390 drivers/media/v4l2-core/v4l2-dev.c:455 > __fput+0x2d7/0x840 fs/file_table.c:280 > task_work_run+0x13f/0x1c0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:163 > prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] > syscall_return_slowpath arch/x86/entry/common.c:274 [inline] > do_syscall_64+0x45f/0x580 arch/x86/entry/common.c:300 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8881c5c54200 > which belongs to the cache kmalloc-8k of size 8192 > The buggy address is located 4136 bytes inside of > 8192-byte region [ffff8881c5c54200, ffff8881c5c56200) > The buggy address belongs to the page: > page:ffffea0007171400 refcount:1 mapcount:0 mapping:ffff8881da00c500 > index:0x0 compound_mapcount: 0 > flags: 0x200000000010200(slab|head) > raw: 0200000000010200 0000000000000000 0000000100000001 ffff8881da00c500 > raw: 0000000000000000 0000000080030003 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8881c5c55100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8881c5c55180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8881c5c55200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff8881c5c55280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff8881c5c55300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > > --- > This bug 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 bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. Most probably the same bug as: https://syzkaller.appspot.com/bug?extid=7fa38a608b1075dfd634 #syz dup: general protection fault in usb_set_interface
