Hello, syzbot found the following crash on: HEAD commit: 0fa84af8 Merge tag 'usb-serial-5.7-rc1' of https://git.ker.. git tree: https://github.com/google/kasan.git usb-fuzzer console output: https://syzkaller.appspot.com/x/log.txt?x=14f1695de00000 kernel config: https://syzkaller.appspot.com/x/.config?x=6b9c154b0c23aecf dashboard link: https://syzkaller.appspot.com/bug?extid=7bf5a7b0f0a1f9446f4c 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+7bf5a7b0f0a1f9446f4c@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in usb_kill_urb drivers/usb/core/urb.c:696 [inline] BUG: KASAN: use-after-free in usb_kill_urb+0x24b/0x2c0 drivers/usb/core/urb.c:688 Read of size 4 at addr ffff8881d8e72310 by task systemd-udevd/5778 CPU: 1 PID: 5778 Comm: systemd-udevd Not tainted 5.6.0-rc7-syzkaller #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+0xef/0x16e lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x314 mm/kasan/report.c:374 __kasan_report.cold+0x37/0x77 mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:641 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x152/0x1c0 mm/kasan/generic.c:192 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] usb_kill_urb drivers/usb/core/urb.c:696 [inline] usb_kill_urb+0x24b/0x2c0 drivers/usb/core/urb.c:688 usbhid_close+0x15c/0x210 drivers/hid/usbhid/hid-core.c:750 hid_hw_close+0xa8/0xd0 drivers/hid/hid-core.c:2100 wacom_close+0x66/0x80 drivers/hid/wacom_sys.c:192 input_close_device+0x110/0x1a0 drivers/input/input.c:682 evdev_close_device drivers/input/evdev.c:428 [inline] evdev_release+0x188/0x1c0 drivers/input/evdev.c:466 __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:164 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fc61b05f270 Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 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 ee fb ff ff 48 89 04 24 RSP: 002b:00007ffc7605c618 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fc61b05f270 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007fc61bf18710 R08: 0000556bb325a33c R09: 0000000000000078 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016 R13: 0000000000000000 R14: 00007ffc7605c6c4 R15: 0000000000000000 Allocated by task 5: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488 kmalloc include/linux/slab.h:560 [inline] usb_alloc_urb+0x65/0xb0 drivers/usb/core/urb.c:74 usbhid_start+0xb26/0x22f0 drivers/hid/usbhid/hid-core.c:1121 hid_hw_start+0x5d/0x130 drivers/hid/hid-core.c:2030 wacom_parse_and_register+0x28f3/0x5260 drivers/hid/wacom_sys.c:2365 wacom_probe+0x94d/0xba0 drivers/hid/wacom_sys.c:2748 hid_device_probe+0x2be/0x3f0 drivers/hid/hid-core.c:2263 really_probe+0x290/0xac0 drivers/base/dd.c:551 driver_probe_device+0x223/0x350 drivers/base/dd.c:724 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431 __device_attach+0x217/0x390 drivers/base/dd.c:897 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0x1459/0x1bf0 drivers/base/core.c:2500 hid_add_device drivers/hid/hid-core.c:2419 [inline] hid_add_device+0x33c/0x9a0 drivers/hid/hid-core.c:2368 usbhid_probe+0xa81/0xfa0 drivers/hid/usbhid/hid-core.c:1386 usb_probe_interface+0x310/0x800 drivers/usb/core/driver.c:374 really_probe+0x290/0xac0 drivers/base/dd.c:551 driver_probe_device+0x223/0x350 drivers/base/dd.c:724 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431 __device_attach+0x217/0x390 drivers/base/dd.c:897 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0x1459/0x1bf0 drivers/base/core.c:2500 usb_set_configuration+0xece/0x1840 drivers/usb/core/message.c:2025 usb_generic_driver_probe+0x9d/0xe0 drivers/usb/core/generic.c:241 usb_probe_device+0xd9/0x230 drivers/usb/core/driver.c:272 really_probe+0x290/0xac0 drivers/base/dd.c:551 driver_probe_device+0x223/0x350 drivers/base/dd.c:724 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431 __device_attach+0x217/0x390 drivers/base/dd.c:897 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0x1459/0x1bf0 drivers/base/core.c:2500 usb_new_device.cold+0x540/0xcd0 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x21cb/0x4300 drivers/usb/core/hub.c:5563 process_one_work+0x94b/0x1620 kernel/workqueue.c:2266 worker_thread+0x96/0xe20 kernel/workqueue.c:2412 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 5: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x117/0x160 mm/kasan/common.c:476 slab_free_hook mm/slub.c:1444 [inline] slab_free_freelist_hook mm/slub.c:1477 [inline] slab_free mm/slub.c:3034 [inline] kfree+0xd5/0x300 mm/slub.c:3995 urb_destroy drivers/usb/core/urb.c:26 [inline] kref_put include/linux/kref.h:65 [inline] usb_free_urb.part.0+0xaf/0x110 drivers/usb/core/urb.c:96 usb_free_urb+0x1b/0x30 drivers/usb/core/urb.c:95 usbhid_stop+0x1d4/0x460 drivers/hid/usbhid/hid-core.c:1217 wacom_remove+0x88/0x3b0 drivers/hid/wacom_sys.c:2772 hid_device_remove+0xed/0x240 drivers/hid/hid-core.c:2296 __device_release_driver drivers/base/dd.c:1135 [inline] device_release_driver_internal+0x231/0x500 drivers/base/dd.c:1168 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533 device_del+0x481/0xd30 drivers/base/core.c:2677 hid_remove_device drivers/hid/hid-core.c:2467 [inline] hid_destroy_device+0xe1/0x150 drivers/hid/hid-core.c:2486 usbhid_disconnect+0x9f/0xe0 drivers/hid/usbhid/hid-core.c:1413 usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:436 __device_release_driver drivers/base/dd.c:1137 [inline] device_release_driver_internal+0x42f/0x500 drivers/base/dd.c:1168 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533 device_del+0x481/0xd30 drivers/base/core.c:2677 usb_disable_device+0x23d/0x790 drivers/usb/core/message.c:1238 usb_disconnect+0x293/0x900 drivers/usb/core/hub.c:2211 hub_port_connect drivers/usb/core/hub.c:5046 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1a1d/0x4300 drivers/usb/core/hub.c:5563 process_one_work+0x94b/0x1620 kernel/workqueue.c:2266 worker_thread+0x96/0xe20 kernel/workqueue.c:2412 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8881d8e72300 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 16 bytes inside of 192-byte region [ffff8881d8e72300, ffff8881d8e723c0) The buggy address belongs to the page: page:ffffea0007639c80 refcount:1 mapcount:0 mapping:ffff8881da002a00 index:0x0 flags: 0x200000000000200(slab) raw: 0200000000000200 ffffea0007628f80 0000000400000004 ffff8881da002a00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881d8e72200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881d8e72280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8881d8e72300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881d8e72380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8881d8e72400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== --- This bug is generated by a bot. 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