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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 ffffc900089bf5f0 by task syz-executor.0/11408

CPU: 0 PID: 11408 Comm: syz-executor.0 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:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:312 [inline]
RIP: 0010:rcu_is_watching+0x37/0xb0 kernel/rcu/tree.c:1092
Code: 1f 23 89 06 48 c7 c3 00 6c 03 00 48 ba 00 00 00 00 00 fc ff df 89 c0 48 8d 3c c5 40 d9 81 89 48 89 f9 48 c1 e9 03 80 3c 11 00 <75> 61 48 03 1c c5 40 d9 81 89 48 b8 00 00 00 00 00 fc ff df 48 8d
RSP: 0018:ffffc900080674b8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000036c00 RCX: 1ffffffff1303b28
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff8981d940
RBP: 000000000045cb29 R08: 0000000000000000 R09: ffffffff8c5a7a27
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc900080675e8
R13: 0000000000000000 R14: ffff8881ba178080 R15: 0000000000000140
 rcu_read_lock include/linux/rcupdate.h:635 [inline]
 is_bpf_text_address+0x11c/0x160 kernel/bpf/core.c:704
 kernel_text_address kernel/extable.c:151 [inline]
 kernel_text_address+0xbd/0xf0 kernel/extable.c:120
 __kernel_text_address+0x9/0x30 kernel/extable.c:105
 unwind_get_return_address arch/x86/kernel/unwind_orc.c:317 [inline]
 unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:312
 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:494
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xae/0x550 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1084 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1175 [inline]
 netlink_sendmsg+0x94f/0xd90 net/netlink/af_netlink.c:1893
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x331/0x810 net/socket.c:2352
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2406
 __sys_sendmmsg+0x195/0x480 net/socket.c:2496
 __do_sys_sendmmsg net/socket.c:2525 [inline]
 __se_sys_sendmmsg net/socket.c:2522 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2522
 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:00007fa41f318c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004fd7a0 RCX: 000000000045cb29
RDX: 010efe10675dec16 RSI: 0000000020000200 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 8701000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000904 R14: 00000000004cbe1c R15: 00007fa41f3196d4


Memory state around the buggy address:
 ffffc900089bf480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900089bf500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900089bf580: 00 00 00 00 f1 f1 f1 f1 00 00 00 00 f3 f3 f3 f3
                                                             ^
 ffffc900089bf600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900089bf680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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