| Message ID | 1453395690-32660-2-git-send-email-stefano.stabellini@eu.citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c index 4e2a27a..8eb3046 100644 --- a/hw/display/xenfb.c +++ b/hw/display/xenfb.c @@ -789,8 +789,9 @@ static void xenfb_handle_events(struct XenFB *xenfb) prod = page->out_prod; out_cons = page->out_cons; - if (prod == out_cons) - return; + if (prod - out_cons >= XENFB_OUT_RING_LEN) { + return; + } xen_rmb(); /* ensure we see ring contents up to prod */ for (cons = out_cons; cons != prod; cons++) { union xenfb_out_event *event = &XENFB_OUT_RING_REF(page, cons);
If the frontend sets out_cons to a value higher than out_prod, it will cause xenfb_handle_events to loop about 2^32 times. Avoid that by using better checks at the beginning of the function. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reported-by: Ling Liu <liuling-it@360.cn> --- hw/display/xenfb.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)