tree 35df965733bf5eacb649569b856efd4572ff6a57
parent 4f84c8d22fc41761051b4f46a9b0da56ffd9757e
author Ruslan Ermilov <ru@nginx.com> 1453815991 +0300
committer Ruslan Ermilov <ru@nginx.com> 1453815991 +0300

Resolver: fixed crashes in timeout handler.

If one or more requests were waiting for a response, then after
getting a CNAME response, the timeout event on the first request
remained active, pointing to the wrong node with an empty
rn->waiting list, and that could cause either null pointer
dereference or use-after-free memory access if this timeout
expired.

If several requests were waiting for a response, and the first
request terminated (e.g., due to client closing a connection),
other requests were left without a timeout and could potentially
wait indefinitely.

This is fixed by introducing per-request independent timeouts.
This change also reverts 954867a2f0a6 and 5004210e8c78.