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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 ffff88809d727b68 by task syz-fuzzer/7995

CPU: 0 PID: 7995 Comm: syz-fuzzer Not tainted 4.14.295-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
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
 alloc_skb include/linux/skbuff.h:980 [inline]
 bcm_can_tx+0x1c1/0x680 net/can/bcm.c:300
 bcm_tx_timeout_tsklet+0x179/0x320 net/can/bcm.c:427
 tasklet_action+0x195/0x340 kernel/softirq.c:513
 __do_softirq+0x24d/0x9ff kernel/softirq.c:288
Bluetooth: hci3 command 0x1407 tx timeout
 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]
 smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1106
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:793
 </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: 0000:ffff88809d727a48 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
RAX: 1ffffffff11e1358 RBX: ffff8880a27ac500 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8880a27acd84
RBP: ffff8880ac5ee118 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: ac5ee080:ep_send_events_proc+0x0/0x9c0
RSP: 9d727c58:0000000000000000 EFLAGS: ffff88809d727d78 ORIG_RAX: ffffffffffffff10
RAX: ffff8880a27ac500 RBX: ffffffff81967220 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff8880ac5ee0b8
RBP: ffff8880ac5ee080 R08: ffffffff8196a317 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809d727d78
R13: 0000000000000000 R14: ffff88809d727c58 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea000275c9c0 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:
 ffff88809d727a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809d727a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88809d727b00: 00 f1 f1 f1 f1 00 00 00 f2 00 00 00 f2 f2 f2 00
                                                          ^
 ffff88809d727b80: 00 00 00 00 f3 f3 f3 f3 f3 00 00 00 00 00 00 00
 ffff88809d727c00: 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 f3 f3 00
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