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BUG: KASAN: stack-out-of-bounds in unwind_next_frame+0x1360/0x17d0 arch/x86/kernel/unwind_orc.c:470
Read of size 8 at addr ffff888095f27b68 by task syz-fuzzer/7994

CPU: 1 PID: 7994 Comm: syz-fuzzer Not tainted 4.14.295-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
 unwind_next_frame+0x1360/0x17d0 arch/x86/kernel/unwind_orc.c:470
 __save_stack_trace+0x90/0x160 arch/x86/kernel/stacktrace.c:44
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 slab_post_alloc_hook mm/slab.h:442 [inline]
 slab_alloc_node mm/slab.c:3333 [inline]
 kmem_cache_alloc_node+0x133/0x410 mm/slab.c:3640
 __alloc_skb+0x5c/0x510 net/core/skbuff.c:193
 __napi_alloc_skb+0x57/0x2d0 net/core/skbuff.c:478
 napi_alloc_skb include/linux/skbuff.h:2721 [inline]
 page_to_skb+0x7b/0x820 drivers/net/virtio_net.c:323
 receive_mergeable drivers/net/virtio_net.c:723 [inline]
 receive_buf+0x1f71/0x4d70 drivers/net/virtio_net.c:828
 virtnet_receive drivers/net/virtio_net.c:1102 [inline]
 virtnet_poll+0x4b7/0x960 drivers/net/virtio_net.c:1193
 napi_poll net/core/dev.c:5604 [inline]
 net_rx_action+0x466/0xfd0 net/core/dev.c:5670
 __do_softirq+0x24d/0x9ff kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x193/0x240 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:638 [inline]
 do_IRQ+0x112/0x1d0 arch/x86/kernel/irq.c:242
 common_interrupt+0x93/0x93 arch/x86/entry/entry_64.S:576
 </IRQ>
RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:774 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:796 [inline]
RIP: 0010:lock_acquire+0x97/0x3f0 kernel/locking/lockdep.c:3993
RSP: 0018:ffff888095f27a48 EFLAGS: 00000286 ORIG_RAX: ffffffffffffffad
RAX: 1ffffffff11e1358 RBX: ffff8880b3650480 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8880b3650d04
RBP: ffff8880b4754118 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 ep_scan_ready_list+0x637/0x7e0 fs/eventpoll.c:693
 retint_kernel+0x2d/0x2d
RIP: b4754080:ep_send_events_proc+0x0/0x9c0
RSP: 95f27c58:0000000000000000 EFLAGS: ffff888095f27d78 ORIG_RAX: ffffffffffffffad
RAX: ffff8880b3650480 RBX: ffffffff81967220 RCX: 1ffff11012be4f87
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b47540b8
RBP: ffff8880b4754080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888095f27d78
R13: 0000000000000000 R14: ffff888095f27c58 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea000257c9c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0xfff00000000000()
raw: 00fff00000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888095f27a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888095f27a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888095f27b00: 00 f1 f1 f1 f1 00 00 00 f2 00 00 00 f2 f2 f2 00
                                                          ^
 ffff888095f27b80: 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00
 ffff888095f27c00: 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f3 f3 00
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