4.16-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jens Axboe <[email protected]> commit f7068114d45ec55996b9040e98111afa56e010fe upstream. We're casting the CDROM layer request_sense to the SCSI sense buffer, but the former is 64 bytes and the latter is 96 bytes. As we generally allocate these on the stack, we end up blowing up the stack. Fix this by wrapping the scsi_execute() call with a properly sized sense buffer, and copying back the bits for the CDROM layer. Cc: [email protected] Reported-by: Piotr Gabriel Kosinski <[email protected]> Reported-by: Daniel Shapira <[email protected]> Tested-by: Kees Cook <[email protected]> Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request") Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/scsi/sr_ioctl.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/scsi/sr_ioctl.c +++ b/drivers/scsi/sr_ioctl.c @@ -188,9 +188,13 @@ int sr_do_ioctl(Scsi_CD *cd, struct pack struct scsi_device *SDev; struct scsi_sense_hdr sshdr; int result, err = 0, retries = 0; + unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE], *senseptr = NULL; SDev = cd->device; + if (cgc->sense) + senseptr = sense_buffer; + retry: if (!scsi_block_when_processing_errors(SDev)) { err = -ENODEV; @@ -198,10 +202,12 @@ int sr_do_ioctl(Scsi_CD *cd, struct pack } result = scsi_execute(SDev, cgc->cmd, cgc->data_direction, - cgc->buffer, cgc->buflen, - (unsigned char *)cgc->sense, &sshdr, + cgc->buffer, cgc->buflen, senseptr, &sshdr, cgc->timeout, IOCTL_RETRIES, 0, 0, NULL); + if (cgc->sense) + memcpy(cgc->sense, sense_buffer, sizeof(*cgc->sense)); + /* Minimal error checking. Ignore cases we know about, and report the rest. */ if (driver_byte(result) != 0) { switch (sshdr.sense_key) {
