From: Mans Rullgard mans@mansr.com
commit 52974d94a206ce428d9d9b6eaa208238024be82a upstream.
When handling a PIO bulk transfer with highmem buffer, a temporary mapping is assigned to urb->transfer_buffer. After the transfer is complete, an invalid address is left behind in this pointer. This is not ordinarily a problem since nothing touches that buffer before the urb is released. However, when usbmon is active, usbmon_urb_complete() calls (indirectly) mon_bin_get_data() which does access the transfer buffer if it is set. To prevent an invalid memory access here, reset urb->transfer_buffer to NULL when finished (musb_host_rx()), or do not set it at all (musb_host_tx()).
Fixes: 8e8a55165469 ("usb: musb: host: Handle highmem in PIO mode") Signed-off-by: Mans Rullgard mans@mansr.com Cc: stable@vger.kernel.org Signed-off-by: Bin Liu b-liu@ti.com Link: https://lore.kernel.org/r/20200316211136.2274-8-b-liu@ti.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/musb/musb_host.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-)
--- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -1519,10 +1519,7 @@ done: * We need to map sg if the transfer_buffer is * NULL. */ - if (!urb->transfer_buffer) - qh->use_sg = true; - - if (qh->use_sg) { + if (!urb->transfer_buffer) { /* sg_miter_start is already done in musb_ep_program */ if (!sg_miter_next(&qh->sg_miter)) { dev_err(musb->controller, "error: sg list empty\n"); @@ -1530,9 +1527,8 @@ done: status = -EINVAL; goto done; } - urb->transfer_buffer = qh->sg_miter.addr; length = min_t(u32, length, qh->sg_miter.length); - musb_write_fifo(hw_ep, length, urb->transfer_buffer); + musb_write_fifo(hw_ep, length, qh->sg_miter.addr); qh->sg_miter.consumed = length; sg_miter_stop(&qh->sg_miter); } else { @@ -1541,11 +1537,6 @@ done:
qh->segsize = length;
- if (qh->use_sg) { - if (offset + length >= urb->transfer_buffer_length) - qh->use_sg = false; - } - musb_ep_select(mbase, epnum); musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY); @@ -2064,8 +2055,10 @@ finish: urb->actual_length += xfer_len; qh->offset += xfer_len; if (done) { - if (qh->use_sg) + if (qh->use_sg) { qh->use_sg = false; + urb->transfer_buffer = NULL; + }
if (urb->status == -EINPROGRESS) urb->status = status;