On 17.12.2013, at 16.43, Yongjian Xu xuyongjiande@xxxxxxxxx wrote: > From: Yongjian Xu <xuyongjiande@xxxxxxxxx> > > mtc.mt_count comes from user-space. > int overflow may occur: > mtc.mt_count++; > mtc.mt_count—; I agree that this is a problem. However, it seems that there is also another problem: the SPACE command uses a 24-bit count field and this overflows far below INT_MAX. Should the count in MTFSF etc. be limited to (2<<24-2)? This would make the checks you suggest unnecessary. (-2 so that the behavior does not depend on whether we are at file mark or not.) I am a bit hesitant with this suggestion because someone may use count INT_MAX to space to the end of the tape. This probably succeeds now but after the fix it would return an error. Thanks, Kai -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
