| From | Ben Hutchings <> | Date | Wed, 15 Feb 2017 22:41:40 +0000 | Subject | [PATCH 3.16 229/306] Fix USB CB/CBI storage devices with CONFIG_VMAP_STACK=y |
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3.16.40-rc1 review patch. If anyone has any objections, please let me know.
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From: Petr Vandrovec <petr@vandrovec.name>
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 <petr@vandrovec.name> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- drivers/usb/storage/transport.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/drivers/usb/storage/transport.c +++ b/drivers/usb/storage/transport.c @@ -919,10 +919,15 @@ int usb_stor_CB_transport(struct scsi_cm /* 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",
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