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BUG: KASAN: use-after-free in debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
BUG: KASAN: use-after-free in do_raw_spin_lock+0x295/0x3a0 kernel/locking/spinlock_debug.c:112
Read of size 4 at addr ffff8880549deecc by task syz-executor.3/3040

CPU: 1 PID: 3040 Comm: syz-executor.3 Not tainted 5.3.0-rc2+ #55
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+0x1d8/0x2f8 lib/dump_stack.c:113
 print_address_description+0x75/0x5b0 mm/kasan/report.c:351
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:482
 kasan_report+0x26/0x50 mm/kasan/common.c:612
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131
 debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
 do_raw_spin_lock+0x295/0x3a0 kernel/locking/spinlock_debug.c:112
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:136 [inline]
 _raw_spin_lock_bh+0x40/0x50 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:343 [inline]
 release_sock+0x30/0x1d0 net/core/sock.c:2932
 nr_release+0x1b9/0x390 net/netrom/af_netrom.c:553
 __sock_release net/socket.c:590 [inline]
 sock_close+0xe1/0x260 net/socket.c:1268
 __fput+0x2e4/0x740 fs/file_table.c:280
 ____fput+0x15/0x20 fs/file_table.c:313
 task_work_run+0x17e/0x1b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x64c/0x2340 kernel/exit.c:878
 do_group_exit+0x15c/0x2b0 kernel/exit.c:982
 get_signal+0x51c/0x1dd0 kernel/signal.c:2728
 do_signal+0x7b/0x720 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x303/0x580 arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274
 do_syscall_64+0x126/0x140 arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: Bad RIP value.
RSP: 002b:00007f4d19835c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002b
RAX: 0000000000000008 RBX: 0000000000000003 RCX: 0000000000459829
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4d198366d4
R13: 00000000004bf6e9 R14: 00000000004d0f80 R15: 00000000ffffffff

Allocated by task 9805:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:487
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:501
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc+0x254/0x340 mm/slab.c:3664
 kmalloc include/linux/slab.h:557 [inline]
 sk_prot_alloc+0xb0/0x290 net/core/sock.c:1603
 sk_alloc+0x38/0x950 net/core/sock.c:1657
 nr_make_new net/netrom/af_netrom.c:476 [inline]
 nr_rx_frame+0xabc/0x1e40 net/netrom/af_netrom.c:959
 nr_loopback_timer+0x6a/0x140 net/netrom/nr_loopback.c:59
 call_timer_fn+0xec/0x200 kernel/time/timer.c:1322
 expire_timers kernel/time/timer.c:1366 [inline]
 __run_timers+0x7cd/0x9c0 kernel/time/timer.c:1685
 run_timer_softirq+0x4a/0x90 kernel/time/timer.c:1698
 __do_softirq+0x333/0x7c4 arch/x86/include/asm/paravirt.h:778

Freed by task 3040:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:449
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:457
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x115/0x200 mm/slab.c:3756
 sk_prot_free net/core/sock.c:1640 [inline]
 __sk_destruct+0x567/0x660 net/core/sock.c:1726
 sk_destruct net/core/sock.c:1734 [inline]
 __sk_free+0x317/0x3e0 net/core/sock.c:1745
 sk_free+0x2a/0x40 net/core/sock.c:1756
 sock_put include/net/sock.h:1725 [inline]
 nr_destroy_socket+0x3e3/0x460 net/netrom/af_netrom.c:288
 nr_release+0x191/0x390 net/netrom/af_netrom.c:530
 __sock_release net/socket.c:590 [inline]
 sock_close+0xe1/0x260 net/socket.c:1268
 __fput+0x2e4/0x740 fs/file_table.c:280
 ____fput+0x15/0x20 fs/file_table.c:313
 task_work_run+0x17e/0x1b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x64c/0x2340 kernel/exit.c:878
 do_group_exit+0x15c/0x2b0 kernel/exit.c:982
 get_signal+0x51c/0x1dd0 kernel/signal.c:2728
 do_signal+0x7b/0x720 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x303/0x580 arch/x86/entry/common.c:194
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274
 do_syscall_64+0x126/0x140 arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880549dee40
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 140 bytes inside of
 2048-byte region [ffff8880549dee40, ffff8880549df640)
The buggy address belongs to the page:
page:ffffea0001527780 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea000285d188 ffffea00028e3588 ffff8880aa400e00
raw: 0000000000000000 ffff8880549de5c0 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880549ded80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880549dee00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8880549dee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8880549def00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880549def80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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