From: Petr Vandrovec Date: Thu, 10 Nov 2016 21:57:14 +0000 (-0800) Subject: Fix USB CB/CBI storage devices with CONFIG_VMAP_STACK=y X-Git-Tag: firefly_0821_release~176^2~4^2~10^2~16 X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=ab0867dd8bc8b33ac662467b2d6cf2aff2516abc;p=firefly-linux-kernel-4.4.55.git Fix USB CB/CBI storage devices with CONFIG_VMAP_STACK=y commit 2ce9d2272b98743b911196c49e7af5841381c206 upstream. Some code (all error handling) submits CDBs that are allocated on the stack. This breaks with CB/CBI code that tries to create URB directly from SCSI command buffer - which happens to be in vmalloced memory with vmalloced kernel stacks. Let's make copy of the command in usb_stor_CB_transport. Signed-off-by: Petr Vandrovec Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c index 5e67f63b2e46..02f86dd1a340 100644 --- a/drivers/usb/storage/transport.c +++ b/drivers/usb/storage/transport.c @@ -919,10 +919,15 @@ int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us) /* COMMAND STAGE */ /* let's send the command via the control pipe */ + /* + * Command is sometime (f.e. after scsi_eh_prep_cmnd) on the stack. + * Stack may be vmallocated. So no DMA for us. Make a copy. + */ + memcpy(us->iobuf, srb->cmnd, srb->cmd_len); result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe, US_CBI_ADSC, USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, - us->ifnum, srb->cmnd, srb->cmd_len); + us->ifnum, us->iobuf, srb->cmd_len); /* check the return code for the command */ usb_stor_dbg(us, "Call to usb_stor_ctrl_transfer() returned %d\n",