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BUG: KASAN: stack-out-of-bounds in user_mode arch/x86/include/asm/ptrace.h:131 [inline]
BUG: KASAN: stack-out-of-bounds in unwind_next_frame+0x19d/0x1f00 arch/x86/kernel/unwind_orc.c:421
Read of size 8 at addr ffff8881a3aa7b90 by task syz-executor.3/4020

CPU: 0 PID: 4020 Comm: syz-executor.3 Not tainted 5.4.96-syzkaller-00126-g72d1876a39cf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x24e lib/dump_stack.c:118
 print_address_description+0x9b/0x650 mm/kasan/report.c:374
 __kasan_report+0x182/0x1f0 mm/kasan/report.c:506
 kasan_report+0x30/0x60 mm/kasan/common.c:634
 user_mode arch/x86/include/asm/ptrace.h:131 [inline]
 unwind_next_frame+0x19d/0x1f00 arch/x86/kernel/unwind_orc.c:421
 arch_stack_walk+0x114/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save_tsk+0x17c/0x270 kernel/stacktrace.c:151
 proc_pid_stack+0x126/0x1f0 fs/proc/base.c:455
 proc_single_show+0xd3/0x120 fs/proc/base.c:757
 seq_read+0x4aa/0xd10 fs/seq_file.c:229
 do_loop_readv_writev fs/read_write.c:714 [inline]
 do_iter_read+0x41b/0x5c0 fs/read_write.c:935
 vfs_readv fs/read_write.c:997 [inline]
 do_preadv+0x20d/0x350 fs/read_write.c:1089
 do_syscall_64+0xcb/0x150 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x465b09
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff70317d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465b09
RDX: 0000000000000375 RSI: 00000000200017c0 RDI: 0000000000000005
RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60
R13: 00007ffeaf74412f R14: 00007ff70317d300 R15: 0000000000022000

The buggy address belongs to the page:
page:ffffea00068ea9c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 ffffea00068eaa08 ffffea00068ea988 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881a3aa7a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881a3aa7b00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
>ffff8881a3aa7b80: 00 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
                         ^
 ffff8881a3aa7c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881a3aa7c80: f1 f1 f1 f1 00 f2 f2 f2 00 00 f3 f3 00 00 00 00
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