tree ee9cdbc1c5681d81d2bb9ad5d906204aad7ef2cd
parent e95f307a7732abc4e4666d64a548a0d6b1c36eb3
author Willy Tarreau <w@1wt.eu> 1674124461 +0100
committer Christopher Faulet <cfaulet@haproxy.com> 1674209626 +0100

BUG/MINOR: listener: close tiny race between resume_listener() and stopping

Pierre Cheynier reported a very rare race condition on soft-stop in the
listeners. What happens is that if a previously limited listener is
being resumed by another thread finishing an accept loop, and at the
same time a soft-stop is performed, the soft-stop will turn the
listener's state to LI_INIT, and once the listener's lock is released,
resume_listener() in the second thread will try to resume this listener
which has an fd==-1, yielding a crash in listener_set_state():

  FATAL: bug condition "l->rx.fd == -1" matched at src/listener.c:288

The reason is that resume_listener() only checks for LI_READY, but doesn't
consider being called with a non-initialized or a stopped listener. Let's
also make sure we don't try to ressuscitate such a listener there.

This will have to be backported to all versions.

(cherry picked from commit d1ebee17740683fd49a88c4064ac1ff6a0dea264)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 87a566b86d0e7c2af9c59ef1c6ba1681c3b4fd21)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 7b27b7d06eb7b9f8afaecb9acc203cc5fae3fcbe)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit b296d45f36ad268c0e34ffb043f639b604d01357)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>