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BUG: KASAN: stack-out-of-bounds in csd_lock_record+0xcb/0xe0 kernel/smp.c:118
Read of size 8 at addr ffffc90016bafbf0 by task syz-executor.1/11039

CPU: 1 PID: 11039 Comm: syz-executor.1 Not tainted 5.8.0-rc3-next-20200703-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+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0x5/0x436 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 csd_lock_record+0xcb/0xe0 kernel/smp.c:118
 flush_smp_call_function_queue+0x285/0x730 kernel/smp.c:391
 __sysvec_call_function_single+0x98/0x490 arch/x86/kernel/smp.c:248
 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706
 </IRQ>
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline]
 sysvec_call_function_single+0xe0/0x120 arch/x86/kernel/smp.c:243
 asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:604
RIP: 0010:rb_first+0xe/0x80 lib/rbtree.c:470
Code: f2 ff ff 4c 89 ff 48 89 04 24 e8 3d c7 02 fe 48 8b 04 24 e9 f8 f5 ff ff 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 53 <48> c1 ea 03 48 83 ec 08 80 3c 02 00 75 46 48 bb 00 00 00 00 00 fc
RSP: 0018:ffffc90017fb78a0 EFLAGS: 00000282
RAX: dffffc0000000000 RBX: 1ffff92002ff6f18 RCX: 0000000000000000
RDX: ffff8880338dfb78 RSI: 0000000000000004 RDI: ffff8880338dfb78
RBP: ffff8880338dfac0 R08: 0000000000000000 R09: ffff8880338dfadb
R10: ffffed100671bf5b R11: 0000000000000000 R12: 0000000000008000
R13: ffff8880338dfb78 R14: dffffc0000000000 R15: fffffbfff1561d20
 pde_subdir_first fs/proc/generic.c:58 [inline]
 remove_proc_entry+0x1b7/0x460 fs/proc/generic.c:700
 can_remove_proc+0x1ae/0x508 net/can/proc.c:484
 can_pernet_exit+0x12/0xe0 net/can/af_can.c:828
 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:186
 setup_net+0x502/0x850 net/core/net_namespace.c:364
 copy_net_ns+0x2cf/0x5e0 net/core/net_namespace.c:482
 create_new_namespaces+0x3f6/0xb10 kernel/nsproxy.c:110
 copy_namespaces+0x385/0x470 kernel/nsproxy.c:179
 copy_process+0x2921/0x6b90 kernel/fork.c:2083
 _do_fork+0x12c/0xa70 kernel/fork.c:2425
 __do_sys_clone+0xef/0x150 kernel/fork.c:2581
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:367
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007f2611992c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00000000004db5a0 RCX: 000000000045cb29
RDX: 9999999999999999 RSI: 0000000000000000 RDI: 0000000050000103
RBP: 000000000078bfa0 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000007c R14: 00000000004c34ba R15: 00007f26119936d4


Memory state around the buggy address:
 ffffc90016bafa80: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
 ffffc90016bafb00: 00 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 f3
>ffffc90016bafb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1
                                                             ^
 ffffc90016bafc00: f1 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00
 ffffc90016bafc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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