tree 830d4b2145707edf3870b87d0707c45913b4829e
parent 7aaf88c7ebee2c766888c9b5f9552207cfdd33b2
author Christopher Faulet <cfaulet@haproxy.com> 1677595178 +0100
committer Christopher Faulet <cfaulet@haproxy.com> 1682089763 +0200

BUG/MEDIUM: connection: Clear flags when a conn is removed from an idle list

When a connection is removed from the safe list or the idle list,
CO_FL_SAFE_LIST and CO_FL_IDLE_LIST flags must be cleared. It is performed
when the connection is reused. But not when it is moved into the
toremove_conns list. It may be an issue because the multiplexer owning the
connection may be woken up before the connection is really removed. If the
connection flags are not sanitized, it may think the connection is idle and
reinsert it in the corresponding list. From this point, we can imagine
several bugs. An UAF or a connection reused with an invalid state for
instance.

To avoid any issue, the connection flags are sanitized when an idle
connection is moved into the toremove_conns list. The same is performed at
right places in the multiplexers. Especially because the connection release
may be delayed (for h2 and fcgi connections).

This patch shoudld fix the issue #2057. It must carefully be backported as
far as 2.2. Especially on the 2.2 where the code is really different. But
some conflicts should be expected on the 2.4 too.

(cherry picked from commit 5e1b0e7bf86a300def07388df0ea7f4b3f9e68b9)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 7902ebadb1ffbe0237ce974b950ca595894f3774)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit d7be206d3570138cfadca87bb768293804629bc7)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 3a132511b973dcb82336427ba1a44fc7ba537cfd)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>