[Qemu-block] [PATCH] throttle: Assert that bkt->max is valid in throttle_compute_wait()

[Alberto Garcia]

If bkt->max == 0 and bkt->burst_length > 1 then we could have a
division by 0 in throttle_do_compute_wait(). That configuration is
however not permitted and is already detected by throttle_is_valid(),
but let's assert it in throttle_compute_wait() to make it explicit.

Found by Coverity (CID: 1381016).

Signed-off-by: Alberto Garcia <address@hidden>
---
 util/throttle.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/util/throttle.c b/util/throttle.c
index 06bf916adc..b38e742da5 100644
--- a/util/throttle.c
+++ b/util/throttle.c
@@ -124,6 +124,7 @@ int64_t throttle_compute_wait(LeakyBucket *bkt)
     /* If the main bucket is not full yet we still have to check the
      * burst bucket in order to enforce the burst limit */
     if (bkt->burst_length > 1) {
+        assert(bkt->max > 0); /* see throttle_is_valid() */
         extra = bkt->burst_level - burst_bucket_size;
         if (extra > 0) {
             return throttle_do_compute_wait(bkt->max, extra);
-- 
2.11.0