From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Subject: [PULL 1/1] vfio: ccw: fix bad ptr math for TIC cda translation Date: Mon, 24 Jul 2017 18:47:01 +0200 Message-ID: <20170724164701.26715-2-cohuck@redhat.com> References: <20170724164701.26715-1-cohuck@redhat.com> Return-path: In-Reply-To: <20170724164701.26715-1-cohuck@redhat.com> Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: schwidefsky@de.ibm.com Cc: bjsdjshi@linux.vnet.ibm.com, borntraeger@de.ibm.com, linux-s390@vger.kernel.org, kvm@vger.kernel.org, "Jason J. Herne" , Cornelia Huck List-ID: From: "Jason J. Herne" When we are translating channel data addresses from guest to host address space for TIC instructions we are getting incorrect addresses because of a pointer arithmetic error. We currently calculate the offset of the TIC's cda from the start of the channel program chain (ccw->cda - ccw_head). We then add that to the address of the ccw chain in host memory (iter->ch_ccw). The problem is that iter->ch_ccw is a pointer to struct ccw1 so when we increment it we are actually incrementing by the size of struct ccw1 which is 8 bytes. The intent was to increment by n-bytes, not n*8. The fix: cast iter->ch_ccw to char* so it will be incremented by n*1. Reviewed-by: Dong Jia Shi Signed-off-by: Jason J. Herne Signed-off-by: Dong Jia Shi Message-Id: <20170721011436.76112-1-bjsdjshi@linux.vnet.ibm.com> Signed-off-by: Cornelia Huck --- drivers/s390/cio/vfio_ccw_cp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index ba6ac83a6c25..5ccfdc80d0ec 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -481,7 +481,7 @@ static int ccwchain_fetch_tic(struct ccwchain *chain, ccw_tail = ccw_head + (iter->ch_len - 1) * sizeof(struct ccw1); if ((ccw_head <= ccw->cda) && (ccw->cda <= ccw_tail)) { - ccw->cda = (__u32) (addr_t) (iter->ch_ccw + + ccw->cda = (__u32) (addr_t) (((char *)iter->ch_ccw) + (ccw->cda - ccw_head)); return 0; } -- 2.13.3