================================================================== BUG: KASAN: out-of-bounds in user_mode arch/x86/include/asm/ptrace.h:126 [inline] BUG: KASAN: out-of-bounds in unwind_next_frame+0x120b/0x1810 arch/x86/kernel/unwind_orc.c:339 Read of size 8 at addr ffff8881ace97540 by task syz-executor.2/4069 CPU: 0 PID: 4069 Comm: syz-executor.2 Not tainted 4.14.155-syzkaller #0 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xe5/0x154 lib/dump_stack.c:58 print_address_description+0x60/0x226 mm/kasan/report.c:187 __kasan_report.cold+0x1a/0x41 mm/kasan/report.c:316 user_mode arch/x86/include/asm/ptrace.h:126 [inline] unwind_next_frame+0x120b/0x1810 arch/x86/kernel/unwind_orc.c:339 __save_stack_trace+0x7a/0xf0 arch/x86/kernel/stacktrace.c:44 save_stack_trace_tsk arch/x86/kernel/stacktrace.c:73 [inline] save_stack_trace_tsk+0x34/0x40 arch/x86/kernel/stacktrace.c:68 proc_pid_stack+0x194/0x270 fs/proc/base.c:460 proc_single_show+0xf1/0x160 fs/proc/base.c:762 seq_read+0x4f7/0x1180 fs/seq_file.c:237 do_loop_readv_writev fs/read_write.c:699 [inline] do_loop_readv_writev fs/read_write.c:686 [inline] do_iter_read+0x3e8/0x5b0 fs/read_write.c:923 vfs_readv+0xe6/0x150 fs/read_write.c:985 do_preadv+0x189/0x230 fs/read_write.c:1069 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a639 RSP: 002b:00007fcbd732cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a639 RDX: 0000000000000332 RSI: 00000000200017c0 RDI: 0000000000000004 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcbd732d6d4 R13: 00000000004c8050 R14: 00000000004de1b8 R15: 00000000ffffffff The buggy address belongs to the page: page:ffffea0006b3a5c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x4000000000000000() raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff raw: 0000000000000000 dead000000000200 0000000000000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ace97400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881ace97480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881ace97500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff8881ace97580: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 ffff8881ace97600: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================