From: Colin Ian King Date: Fri, 3 Nov 2017 08:42:02 +0000 (+0000) Subject: xen/pvcalls: fix unsigned less than zero error check X-Git-Tag: v4.15-rc1~78^2~15 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=95110ac88d5139c73eef6ede37eff23c4089f4f2;p=linux.git xen/pvcalls: fix unsigned less than zero error check The check on bedata->ref is never true because ref is an unsigned integer. Fix this by assigning signed int ret to the return of the call to gnttab_claim_grant_reference so the -ve return can be checked. Detected by CoverityScan, CID#1460358 ("Unsigned compared against 0") Fixes: 219681909913 ("xen/pvcalls: connect to the backend") Signed-off-by: Colin Ian King Reviewed-by: Juergen Gross Signed-off-by: Boris Ostrovsky --- diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index ed94ea0b4b8e..60a0ad81d4cf 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -1186,11 +1186,10 @@ static int pvcalls_front_probe(struct xenbus_device *dev, ret = gnttab_alloc_grant_references(1, &gref_head); if (ret < 0) goto error; - bedata->ref = gnttab_claim_grant_reference(&gref_head); - if (bedata->ref < 0) { - ret = bedata->ref; + ret = gnttab_claim_grant_reference(&gref_head); + if (ret < 0) goto error; - } + bedata->ref = ret; gnttab_grant_foreign_access_ref(bedata->ref, dev->otherend_id, virt_to_gfn((void *)sring), 0);