strange data in logs, `file_report_buffer: expected 2 bytes, but got 512 `

[fenugrec]

strange data in logs, `file_report_buffer: expected 2 bytes, but got 512 `

[jimklimov]

The decoding should have started earlier, with 34 64 00 00 00 00 00 00 d0 12 2d 0b 1b 5d 00 00 line - and it ends the string with 0x00 after two bytes of data ;)

On one hand, it is indeed odd that it returns 512 bytes, using an uninitialized memory block. By content, it was memory that once belonged to the process and was since freed. So the bytes in it are not too much surprising, the length is. Code comments are about broken device report descriptors, so maybe that's just it - many vendors can't read USB specs well.

[fenugrec]

Just some notes as I look at this superficially ;

HIDGetEvents() has

        r = (interrupt_size > 0 && interrupt_size < sizeof(buf))
                 ? interrupt_size : sizeof(buf);

where sizeof(buf) == SMALLBUF == 512. This would be used if interrupt_size is <=0; this (global !) variable is set in usbhid-ups.c from (I think) a config key "interruptsize". I wonder if it's set to 0 by default ?