There are a number of bugs here:
1) If "count" is less than sizeof(dump_data.data) then it copies
uninitialized data.
2) If simple_write_to_buffer() returns -EFAULT then we run into a
problem "ret < count" comparison. "count" is an unsigned long so the
comparison is type promoted to unsigned long and the negative returns
become high positive values. That also results in copying
uninitialized data.
3) If "*ppos" is non-zero then the first part of the dump_data
buffer is uninitialized. Using copy_from_user() instead of
simple_write_to_buffer() is more appropriate here.
Fixes: d5d5df6da0aa ("Bluetooth: Add vhci devcoredump support")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
e4eea89036