Daniel P. Berrangé <berra...@redhat.com> writes: > Two previous attempts to fix this due to GCC 9 highlighting > unaligned data access. My attempt: > > https://lists.gnu.org/archive/html/qemu-devel/2019-03/msg07763.html > > And a previous one: > > https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg07923.html > https://lists.gnu.org/archive/html/qemu-devel/2019-03/msg00162.html > > There are a number of bugs in the USB MTP usb_mtp_write_metadata > method handling the filename character set conversion. > > The 2nd patch in this series is a security flaw fix since the > code was not correctly validating guest provided data length. > > I've been unable to figure out how to exercise the codepath that > calls usb_mtp_write_metadata. At a guess, it looks like something > that should be called when writing to a file from a guest, but the > GNOME GVFS MTP driver doesn't provide write support. Using the > command line MTP tools "mtp-sendfile" command results in an > protocol error > > # mtp-sendfile foo eek.txt > libmtp version: 1.1.14 >
The store is read only by default. Are you trying something like: -device usb-mtp,rootdir=/code/mtpshare,readonly=false ? BTW, I also found a bug introduced by a recent commit which will return an incomplete transfer for smaller file sizes. > Device 0 (VID=46f4 and PID=0004) is UNKNOWN in libmtp v1.1.14. > Please report this VID/PID and the device model to the libmtp development > team > PTP_ERROR_IO: failed to open session, trying again after resetting USB > interface > LIBMTP libusb: Attempt to reset device > Sending foo to eek.txt > type: , 44 > Sending file... > > Error sending file. > Error 2: PTP Layer error 02ff: send_file_object_info(): Could not send > object info. > Error 2: Error 02ff: PTP I/O Error > ERROR: Could not close session! > > And QEMU tracing show unexpected requests > > 26582@1555340076151600935 usb_mtp_command dev 4, code 0x9803, trans 0x18, > args 0x11, 0xdc04, 0x0, 0x0, 0x0 > 26582@1555340076151619955 usb_mtp_xfer dev 4, ep 2, 20/20 > 26582@1555340076154138556 usb_mtp_data_in dev 4, trans 0x18, len 8 > 26582@1555340076154150689 usb_mtp_xfer dev 4, ep 1, 20/512 > 26582@1555340076156654311 usb_mtp_success dev 4, trans 0x18, args 0x0, 0x0 > 26582@1555340076156667764 usb_mtp_xfer dev 4, ep 1, 12/512 > 26582@1555340076159215930 usb_mtp_command dev 4, code 0x100c, trans 0x19, > args 0x10001, 0xc, 0x0, 0x0, 0x0 > 26582@1555340076159229610 usb_mtp_xfer dev 4, ep 2, 20/20 > 26582@1555340076164166196 usb_mtp_stall dev 4, reason: awaiting data-out > 26582@1555340076167156367 usb_mtp_stall dev 4, reason: transaction > inflight > 26582@1555340076170108336 usb_mtp_stall dev 4, reason: unknown control > request > 26582@1555340076172606798 usb_mtp_stall dev 4, reason: unknown control > request > > Perhaps a Windows guest can exercise this, but I don't have a modern > Windows install with MTP support. > > Thus this series is merely compile tested. > > Daniel P. Berrangé (3): > usb-mtp: fix string length for filename when writing metadata > usb-mtp: fix bounds check for guest provided filename > usb-mtp: fix alignment of access of ObjectInfo filename field > > hw/usb/dev-mtp.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-)
