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=126f75d7e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=6b9c154b0c23aecf dashboard link: https://syzkaller.appspot.com/bug?extid=be5b5f86a162a6c281e6 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+be5b5f86a162a6c281e6@xxxxxxxxxxxxxxxxxxxxxxxxx usblp0: nonzero read bulk status received: -71 ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x31af/0x3b60 kernel/locking/lockdep.c:3827 Read of size 8 at addr ffff8881c4563920 by task systemd-udevd/154 CPU: 0 PID: 154 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: <IRQ> __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 __lock_acquire+0x31af/0x3b60 kernel/locking/lockdep.c:3827 lock_acquire+0x130/0x340 kernel/locking/lockdep.c:4484 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x32/0x50 kernel/locking/spinlock.c:159 usblp_bulk_read+0x211/0x270 drivers/usb/class/usblp.c:303 __usb_hcd_giveback_urb+0x1f2/0x470 drivers/usb/core/hcd.c:1648 usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1713 dummy_timer+0x1258/0x32ae drivers/usb/gadget/udc/dummy_hcd.c:1966 call_timer_fn+0x195/0x6f0 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x5f9/0x1500 kernel/time/timer.c:1786 __do_softirq+0x21e/0x950 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x178/0x1a0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] smp_apic_timer_interrupt+0x141/0x540 arch/x86/kernel/apic/apic.c:1146 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 </IRQ> RIP: 0010:unwind_next_frame+0x160/0x19e0 arch/x86/kernel/unwind_orc.c:407 Code: 88 00 00 00 03 0f 85 07 05 00 00 4c 8d 63 35 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 0f b6 04 02 4c 89 e2 83 e2 07 <38> d0 7f 08 84 c0 0f 85 6f 0b 00 00 4c 89 f1 0f b6 43 35 48 ba 00 RSP: 0018:ffff8881cf93f598 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: ffff8881cf93f670 RCX: 0000000000000001 RDX: 0000000000000005 RSI: 0000000000000000 RDI: ffff8881cf93f670 RBP: 1ffff11039f27ebb R08: 0000000000000001 R09: 0000000000000001 R10: 000000000001af58 R11: 0000000000000001 R12: ffff8881cf93f6a5 R13: ffff8881cf93f6c0 R14: ffff8881cf93f6b8 R15: 0000000000000001 arch_stack_walk+0x74/0xd0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 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 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2786 [inline] slab_alloc mm/slub.c:2794 [inline] kmem_cache_alloc+0xd8/0x300 mm/slub.c:2799 anon_vma_alloc mm/rmap.c:83 [inline] anon_vma_fork+0xed/0x490 mm/rmap.c:361 dup_mmap kernel/fork.c:559 [inline] dup_mm+0x8e6/0x1180 kernel/fork.c:1360 copy_mm kernel/fork.c:1416 [inline] copy_process+0x26ef/0x6640 kernel/fork.c:2081 _do_fork+0x12d/0xfd0 kernel/fork.c:2430 __do_sys_clone kernel/fork.c:2585 [inline] __se_sys_clone kernel/fork.c:2566 [inline] __x64_sys_clone+0x182/0x210 kernel/fork.c:2566 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fb33d81138b Code: db 45 85 f6 0f 85 95 01 00 00 64 4c 8b 04 25 10 00 00 00 31 d2 4d 8d 90 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 de 00 00 00 85 c0 41 89 c5 0f 85 e5 00 00 RSP: 002b:00007ffcdbdc01b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffcdbdc01b0 RCX: 00007fb33d81138b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffcdbdc0200 R08: 00007fb33e9c18c0 R09: 0000000000000210 R10: 00007fb33e9c1b90 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000020 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 3361: 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:555 [inline] kzalloc include/linux/slab.h:669 [inline] usblp_probe+0xed/0x1200 drivers/usb/class/usblp.c:1104 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 12266: 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 usblp_disconnect.cold+0x24/0x29 drivers/usb/class/usblp.c:1380 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 ffff8881c4563800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 288 bytes inside of 1024-byte region [ffff8881c4563800, ffff8881c4563c00) The buggy address belongs to the page: page:ffffea0007115800 refcount:1 mapcount:0 mapping:ffff8881da002280 index:0x0 compound_mapcount: 0 flags: 0x200000000010200(slab|head) raw: 0200000000010200 ffffea00074d3000 0000000400000004 ffff8881da002280 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881c4563800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881c4563880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881c4563900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881c4563980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881c4563a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This bug is generated by a bot. 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