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BUG: KASAN: alloca-out-of-bounds in unwind_next_frame.part.7+0x6ce/0x9c0 arch/x86/kernel/unwind_frame.c:324
Read of size 8 at addr ffff88018cfef268 by task syz-executor2/20636

CPU: 1 PID: 20636 Comm: syz-executor2 Not tainted 4.16.0+ #4
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+0x1b9/0x294 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0xac/0x2f5 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 unwind_next_frame.part.7+0x6ce/0x9c0 arch/x86/kernel/unwind_frame.c:324
 unwind_next_frame+0x3e/0x50 arch/x86/kernel/unwind_frame.c:287
 __save_stack_trace+0x6e/0xd0 arch/x86/kernel/stacktrace.c:44
 save_stack_trace+0x1a/0x20 arch/x86/kernel/stacktrace.c:60
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527
 __cache_free mm/slab.c:3486 [inline]
 kmem_cache_free+0x86/0x2d0 mm/slab.c:3744
 put_cred_rcu+0x2bd/0x460 kernel/cred.c:126
 __rcu_reclaim kernel/rcu/rcu.h:178 [inline]
 rcu_do_batch kernel/rcu/tree.c:2675 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2930 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2897 [inline]
 rcu_process_callbacks+0x941/0x15f0 kernel/rcu/tree.c:2914
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
 invoke_softirq kernel/softirq.c:365 [inline]
 irq_exit+0x1d1/0x200 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:525 [inline]
 smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:862
 </IRQ>
RIP: 0010:kasan_unpoison_shadow+0x0/0x50 mm/kasan/kasan.c:51
RSP: 0018:ffff88018cfef2f8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 0000000000040000 RBX: ffffffff86015680 RCX: ffffc900030c9000
RDX: 0000000000000223 RSI: 00000000000000b0 RDI: ffff88018cfef260
RBP: ffff88018cfef300 R08: ffff880189e8a700 R09: fffffbfff15d0626
R10: fffffbfff15d0626 R11: ffffffff8ae83137 R12: 00000000ffffefff
R13: 000000000000000c R14: 00000000ffffefff R15: ffff8801b62e1500
 rcu_lock_release include/linux/rcupdate.h:251 [inline]
 rcu_read_unlock include/linux/rcupdate.h:688 [inline]
 nfnetlink_rcv_msg+0x6af/0xfe0 net/netfilter/nfnetlink.c:196
 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2446
 nfnetlink_rcv+0x1fe/0x1ba0 net/netfilter/nfnetlink.c:513
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x9d8/0xf80 net/netlink/af_netlink.c:1899
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 ___sys_sendmsg+0x805/0x940 net/socket.c:2117
 __sys_sendmsg+0x115/0x270 net/socket.c:2155
 SYSC_sendmsg net/socket.c:2164 [inline]
 SyS_sendmsg+0x29/0x30 net/socket.c:2162
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x455259
RSP: 002b:00007fad0bfafc68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fad0bfb06d4 RCX: 0000000000455259
RDX: 0000000000000000 RSI: 0000000020aba000 RDI: 0000000000000014
RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000004f0 R14: 00000000006fa720 R15: 0000000000000001

The buggy address belongs to the page:
page:ffffea000633fbc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 ffffea0006330101 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88018cfef100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88018cfef180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88018cfef200: 00 00 00 00 00 00 00 00 00 00 00 00 ca ca ca ca
                                                          ^
 ffff88018cfef280: 00 00 00 00 00 00 00 00 00 00 00 cb cb cb cb cb
 ffff88018cfef300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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