==================================================================
BUG: KMSAN: kernel-infoleak in _copy_to_user+0x16b/0x1f0 /lib/usercopy.c:32
CPU: 0 PID: 27875 Comm: syz-executor.5 Not tainted 5.2.0+ #15
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+0x191/0x1f0 /lib/dump_stack.c:113
 kmsan_report+0x162/0x2d0 /mm/kmsan/kmsan_report.c:109
 kmsan_internal_check_memory+0x974/0xa80 /mm/kmsan/kmsan.c:551
 kmsan_copy_to_user+0xa9/0xb0 /mm/kmsan/kmsan_hooks.c:493
 _copy_to_user+0x16b/0x1f0 /lib/usercopy.c:32
 copy_to_user /./include/linux/uaccess.h:174 [inline]
 fuzzer_ioctl_ep0_read /drivers/usb/gadget/fuzzer/fuzzer.c:982 [inline]
 fuzzer_ioctl+0x511f/0x5690 /drivers/usb/gadget/fuzzer/fuzzer.c:1398
 full_proxy_unlocked_ioctl+0x222/0x330 /fs/debugfs/file.c:205
 do_vfs_ioctl+0xea8/0x2c50 /fs/ioctl.c:46
 ksys_ioctl /fs/ioctl.c:713 [inline]
 __do_sys_ioctl /fs/ioctl.c:720 [inline]
 __se_sys_ioctl+0x1da/0x270 /fs/ioctl.c:718
 __x64_sys_ioctl+0x4a/0x70 /fs/ioctl.c:718
 do_syscall_64+0xbc/0xf0 /arch/x86/entry/common.c:302
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x459687
Code: 48 83 c4 08 48 89 d8 5b 5d c3 66 0f 1f 84 00 00 00 00 00 48 89 e8 48 f7 d8 48 39 c3 0f 92 c0 eb 92 66 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 5d b9 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f64914cf3e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000459687
RDX: 00007f64914cf420 RSI: 00000000c0085504 RDI: 0000000000000003
RBP: 0000000000000040 R08: 0000000000000000 R09: 000000000000000f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f64914d06d4
R13: 00000000004bee6a R14: 00000000004dfa90 R15: 00000000ffffffff

Uninit was created at:
 kmsan_save_stack_with_flags /mm/kmsan/kmsan.c:187 [inline]
 kmsan_internal_poison_shadow+0x53/0xa0 /mm/kmsan/kmsan.c:146
 kmsan_slab_alloc+0xaa/0x120 /mm/kmsan/kmsan_hooks.c:175
 slab_alloc_node /mm/slub.c:2771 [inline]
 slab_alloc /mm/slub.c:2780 [inline]
 __kmalloc+0x273/0x370 /mm/slub.c:3815
 kmalloc /./include/linux/slab.h:552 [inline]
 fuzzer_ioctl_ep0_read /drivers/usb/gadget/fuzzer/fuzzer.c:926 [inline]
 fuzzer_ioctl+0x2b09/0x5690 /drivers/usb/gadget/fuzzer/fuzzer.c:1398
 full_proxy_unlocked_ioctl+0x222/0x330 /fs/debugfs/file.c:205
 do_vfs_ioctl+0xea8/0x2c50 /fs/ioctl.c:46
 ksys_ioctl /fs/ioctl.c:713 [inline]
 __do_sys_ioctl /fs/ioctl.c:720 [inline]
 __se_sys_ioctl+0x1da/0x270 /fs/ioctl.c:718
 __x64_sys_ioctl+0x4a/0x70 /fs/ioctl.c:718
 do_syscall_64+0xbc/0xf0 /arch/x86/entry/common.c:302
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Byte 0 of 1 is uninitialized
Memory access of size 1 starts at ffff88803b1eeda0
Data copied to user address 00007f64914cf428
==================================================================