From f7068114d45ec55996b9040e98111afa56e010fe Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 21 May 2018 12:21:14 -0600 Subject: sr: pass down correctly sized SCSI sense buffer 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: stable@vger.kernel.org Reported-by: Piotr Gabriel Kosinski Reported-by: Daniel Shapira Tested-by: Kees Cook Fixes: 82ed4db499b8 ("block: split scsi_request out of struct request") Signed-off-by: Jens Axboe --- drivers/scsi/sr_ioctl.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'drivers/scsi/sr_ioctl.c') diff --git a/drivers/scsi/sr_ioctl.c b/drivers/scsi/sr_ioctl.c index 2a21f2d48592..35fab1e18adc 100644 --- a/drivers/scsi/sr_ioctl.c +++ b/drivers/scsi/sr_ioctl.c @@ -188,9 +188,13 @@ int sr_do_ioctl(Scsi_CD *cd, struct packet_command *cgc) 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 packet_command *cgc) } 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) { -- cgit