Skip to content
Permalink
Browse files Browse the repository at this point in the history
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 <pg.kosinski@gmail.com>
Reported-by: Daniel Shapira <daniel@twistlock.com>
Tested-by: Kees Cook <keescook@chromium.org>
Fixes: 82ed4db ("block: split scsi_request out of struct request")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
  • Loading branch information
axboe committed May 21, 2018
1 parent 1c1a2ee commit f706811
Showing 1 changed file with 8 additions and 2 deletions.
10 changes: 8 additions & 2 deletions drivers/scsi/sr_ioctl.c
Expand Up @@ -188,20 +188,26 @@ 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;
goto out;
}

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) {
Expand Down

0 comments on commit f706811

Please sign in to comment.