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BUG: KMSAN: kernel-infoleak in _copy_to_user+0x19a/0x230 lib/usercopy.c:31
CPU: 0 PID: 21789 Comm: syz-executor4 Not tainted 4.20.0-rc3+ #90
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+0x32d/0x480 lib/dump_stack.c:113
 kmsan_report+0x19f/0x300 mm/kmsan/kmsan.c:911
 kmsan_internal_check_memory+0x52b/0xa60 mm/kmsan/kmsan.c:986
 kmsan_copy_to_user+0x7c/0xe0 mm/kmsan/kmsan_hooks.c:552
 _copy_to_user+0x19a/0x230 lib/usercopy.c:31
 copy_to_user include/linux/uaccess.h:183 [inline]
 copy_siginfo_to_user+0x80/0x1b0 kernel/signal.c:2921
 ptrace_peek_siginfo kernel/ptrace.c:751 [inline]
 ptrace_request+0x256a/0x29c0 kernel/ptrace.c:922
 arch_ptrace+0xb66/0x1150 arch/x86/kernel/ptrace.c:867
 __do_sys_ptrace kernel/ptrace.c:1154 [inline]
 __se_sys_ptrace+0x46c/0x990 kernel/ptrace.c:1119
 __x64_sys_ptrace+0x56/0x70 kernel/ptrace.c:1119
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457569
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:00007fbdce1c2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000065
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569
RDX: 00000000200000c0 RSI: 0000000000000146 RDI: 0000000000004209
RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000070f000 R11: 0000000000000246 R12: 00007fbdce1c36d4
R13: 00000000004c3882 R14: 00000000004d5ce0 R15: 00000000ffffffff

Local variable description: ----kiov@ptrace_request
Variable was created at:
 ptrace_request+0x1a9/0x29c0 kernel/ptrace.c:895
 arch_ptrace+0xb66/0x1150 arch/x86/kernel/ptrace.c:867

Bytes 0-15 of 48 are uninitialized
Memory access of size 48 starts at ffff8880a8fafd50
Data copied to user address 000000000070f000
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