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BUG: KMSAN: kernel-infoleak in _copy_to_user+0x1a4/0x250 lib/usercopy.c:32
CPU: 1 PID: 8635 Comm: syz-executor5 Not tainted 4.20.0-rc5+ #112
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+0x1c9/0x220 lib/dump_stack.c:113
 kmsan_report+0x12d/0x290 mm/kmsan/kmsan.c:684
 kmsan_internal_check_memory+0x514/0xa50 mm/kmsan/kmsan.c:758
 kmsan_copy_to_user+0x8d/0xa0 mm/kmsan/kmsan_hooks.c:620
 _copy_to_user+0x1a4/0x250 lib/usercopy.c:32
 copy_to_user include/linux/uaccess.h:177 [inline]
 copy_siginfo_to_user+0x80/0x160 kernel/signal.c:2921
 ptrace_peek_siginfo kernel/ptrace.c:741 [inline]
 ptrace_request+0x2421/0x2860 kernel/ptrace.c:912
 arch_ptrace+0xa4a/0x1000 arch/x86/kernel/ptrace.c:867
 __do_sys_ptrace kernel/ptrace.c:1144 [inline]
 __se_sys_ptrace+0x359/0x890 kernel/ptrace.c:1109
 __x64_sys_ptrace+0x56/0x70 kernel/ptrace.c:1109
 do_syscall_64+0xcd/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457679
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f6b190e5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000065
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457679
RDX: 00000000200000c0 RSI: 000000000000013e RDI: 0000000000004209
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000070f000 R11: 0000000000000246 R12: 00007f6b190e66d4
R13: 00000000004c3a83 R14: 00000000004d6550 R15: 00000000ffffffff

Local variable description: ----kiov@ptrace_request
Variable was created at:
 ptrace_request+0x194/0x2860 kernel/ptrace.c:885
 arch_ptrace+0xa4a/0x1000 arch/x86/kernel/ptrace.c:867

Bytes 0-15 of 48 are uninitialized
Memory access of size 48 starts at ffff888129b4fd78
Data copied to user address 000000000070f000
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