These are signed values the come from the user, we put a cap on the upper bounds but not on the lower bounds. We use "karg.dataSgeOffset" to calculate "sz". We verify "sz" and proceed as if that means that "karg.dataSgeOffset" is correct but this fails to consider that the "sz" calculations can have integer overflows. Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> --- During my QC process, I realized that I sent a similar patch last year, but never received a response. http://permalink.gmane.org/gmane.linux.kernel.janitors/32590 Looking at both of them, I guess I prefer today's patch because it is simpler. diff --git a/drivers/message/fusion/mptctl.c b/drivers/message/fusion/mptctl.c index 70bb753..fc73937 100644 --- a/drivers/message/fusion/mptctl.c +++ b/drivers/message/fusion/mptctl.c @@ -1859,6 +1859,15 @@ mptctl_do_mpt_command (struct mpt_ioctl_command karg, void __user *mfPtr) } spin_unlock_irqrestore(&ioc->taskmgmt_lock, flags); + /* Basic sanity checks to prevent underflows or integer overflows */ + if (karg.maxReplyBytes < 0 || + karg.dataInSize < 0 || + karg.dataOutSize < 0 || + karg.dataSgeOffset < 0 || + karg.maxSenseBytes < 0 || + karg.dataSgeOffset > ioc->req_sz / 4) + return -EINVAL; + /* Verify that the final request frame will not be too large. */ sz = karg.dataSgeOffset * 4; -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
