3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Thumshirn <jthumshirn@xxxxxxx> commit 14074aba4bcda3764c9a702b276308b89901d5b6 upstream. dxfer_len is an unsigned int and we always assign a value > 0 to it, so it doesn't make any sense to check if it is < 0. We can't really check dxferp as well as we have both NULL and not NULL cases in the possible call paths. So just return true for SG_DXFER_FROM_DEV transfer in sg_is_valid_dxfer(). Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Reported-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/scsi/sg.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -770,8 +770,11 @@ static bool sg_is_valid_dxfer(sg_io_hdr_ return false; return true; case SG_DXFER_FROM_DEV: - if (hp->dxfer_len < 0) - return false; + /* + * 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: