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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 ffffc9000ed879d0 by task kworker/u4:4/9539

CPU: 0 PID: 9539 Comm: kworker/u4:4 Not tainted 5.8.0-rc3-next-20200703-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
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:check_preemption_disabled+0x31/0x130 lib/smp_processor_id.c:16
Code: 41 54 55 48 89 fd 53 0f 1f 44 00 00 65 44 8b 25 a5 9c 17 78 65 8b 1d be 07 18 78 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 <85> db 74 11 0f 1f 44 00 00 44 89 e0 5b 5d 41 5c 41 5d 41 5e c3 0f
RSP: 0018:ffffc9000871fc38 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff87cec677
RDX: ffff8880a2a76100 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffffff8893c040 R08: 0000000000000000 R09: ffffffff8c5a7a27
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8893c000 R14: dffffc0000000000 R15: 00000000000000ae
 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:312 [inline]
 rcu_is_watching+0x11/0xb0 kernel/rcu/tree.c:1092
 rcu_read_lock include/linux/rcupdate.h:635 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline]
 batadv_nc_worker+0xa26/0xe50 net/batman-adv/network-coding.c:718
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294


Memory state around the buggy address:
 ffffc9000ed87880: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
 ffffc9000ed87900: 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00
>ffffc9000ed87980: 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00
                                                 ^
 ffffc9000ed87a00: f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000ed87a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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