| Message ID | 20170727071126.4717-1-jthumshirn@suse.de (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On 07/27/2017 09:11 AM, Johannes Thumshirn wrote: > Don't make any assumptions on the sg_io_hdr_t::dxfer_direction or the > sg_io_hdr_t::dxferp in order to determine if it is a valid request. The > only way we can check for bad requests is by checking if the length exceeds > 256M. > > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> > Fixes: 28676d869bbb (scsi: sg: check for valid direction before starting the > request) > Reported-by: Jason L Tibbitts III <tibbs@math.uh.edu> > Tested-by: Jason L Tibbitts III <tibbs@math.uh.edu> > Suggested-by: Doug Gilbert <dgilbert@interlog.com> > Cc: Doug Gilbert <dgilbert@interlog.com> > Cc: <stable@vger.kernel.org> > --- > drivers/scsi/sg.c | 31 +------------------------------ > 1 file changed, 1 insertion(+), 30 deletions(-) > Reviewed-by: Hannes Reinecke <hare@suse.com> Cheers, Hannes
Johannes, > Don't make any assumptions on the sg_io_hdr_t::dxfer_direction or the > sg_io_hdr_t::dxferp in order to determine if it is a valid > request. The only way we can check for bad requests is by checking if > the length exceeds 256M. Applied to 4.13/scsi-fixes. Thanks!
>>>>> "MKP" == Martin K Petersen <martin.petersen@oracle.com> writes:
MKP> Applied to 4.13/scsi-fixes. Thanks!
My thanks as well to everyone who helped in getting this fixed.
- J<
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 4fe606b000b4..d7ff71e0c85c 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -751,35 +751,6 @@ sg_new_write(Sg_fd *sfp, struct file *file, const char __user *buf, return count; } -static bool sg_is_valid_dxfer(sg_io_hdr_t *hp) -{ - switch (hp->dxfer_direction) { - case SG_DXFER_NONE: - if (hp->dxferp || hp->dxfer_len > 0) - return false; - return true; - case SG_DXFER_FROM_DEV: - /* - * for SG_DXFER_FROM_DEV we always set dxfer_len to > 0. dxferp - * can either be NULL or != NULL so there's no point in checking - * it either. So just return true. - */ - return true; - case SG_DXFER_TO_DEV: - case SG_DXFER_TO_FROM_DEV: - if (!hp->dxferp || hp->dxfer_len == 0) - return false; - return true; - case SG_DXFER_UNKNOWN: - if ((!hp->dxferp && hp->dxfer_len) || - (hp->dxferp && hp->dxfer_len == 0)) - return false; - return true; - default: - return false; - } -} - static int sg_common_write(Sg_fd * sfp, Sg_request * srp, unsigned char *cmnd, int timeout, int blocking) @@ -800,7 +771,7 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp, "sg_common_write: scsi opcode=0x%02x, cmd_size=%d\n", (int) cmnd[0], (int) hp->cmd_len)); - if (!sg_is_valid_dxfer(hp)) + if (hp->dxfer_len >= SZ_256M) return -EINVAL; k = sg_start_req(srp, cmnd);