Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commitb37c90f

Browse files
committed
Fix SSL deadlock risk in libpq
In libpq, we set up and pass to OpenSSL callback routines to handlelocking. When we run out of SSL connections, we try to clean thingsup by de-registering the hooks. Unfortunately, we had a few callsinto the OpenSSL library after these hooks were de-registered duringSSL cleanup which lead to deadlocking. This moves the thread callbackcleanup to be after all SSL-cleanup related OpenSSL library calls.I've been unable to reproduce the deadlock with this fix.In passing, also move the close_SSL call to be after unlocking ourssl_config mutex when in a failure state. While it looks prettyunlikely to be an issue, it could have resulted in deadlocks if weended up in this code path due to something other than SSL_newfailing. Thanks to Heikki for pointing this out.Back-patch to all supported versions; note that the close_SSL issueonly goes back to 9.0, so that hunk isn't included in the 8.4 patch.Initially found and reported by Vesa-Matti J Kari; many thanks toboth Heikki and Andres for their help running down the specificissue and reviewing the patch.
1 parentb882246 commitb37c90f

File tree

1 file changed

+22
-2
lines changed

1 file changed

+22
-2
lines changed

‎src/interfaces/libpq/fe-secure.c

Lines changed: 22 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -282,10 +282,11 @@ pqsecure_open_client(PGconn *conn)
282282
libpq_gettext("could not establish SSL connection: %s\n"),
283283
err);
284284
SSLerrfree(err);
285-
close_SSL(conn);
286285
#ifdefENABLE_THREAD_SAFETY
287286
pthread_mutex_unlock(&ssl_config_mutex);
288287
#endif
288+
close_SSL(conn);
289+
289290
returnPGRES_POLLING_FAILED;
290291
}
291292
#ifdefENABLE_THREAD_SAFETY
@@ -1537,15 +1538,23 @@ open_client_SSL(PGconn *conn)
15371538
staticvoid
15381539
close_SSL(PGconn*conn)
15391540
{
1541+
booldestroy_needed= false;
1542+
15401543
if (conn->ssl)
15411544
{
15421545
DECLARE_SIGPIPE_INFO(spinfo);
15431546

1547+
/*
1548+
* We can't destroy everything SSL-related here due to the possible
1549+
* later calls to OpenSSL routines which may need our thread
1550+
* callbacks, so set a flag here and check at the end.
1551+
*/
1552+
destroy_needed= true;
1553+
15441554
DISABLE_SIGPIPE(conn,spinfo, (void)0);
15451555
SSL_shutdown(conn->ssl);
15461556
SSL_free(conn->ssl);
15471557
conn->ssl=NULL;
1548-
pqsecure_destroy();
15491558
/* We have to assume we got EPIPE */
15501559
REMEMBER_EPIPE(spinfo, true);
15511560
RESTORE_SIGPIPE(conn,spinfo);
@@ -1565,6 +1574,17 @@ close_SSL(PGconn *conn)
15651574
conn->engine=NULL;
15661575
}
15671576
#endif
1577+
1578+
/*
1579+
* This will remove our SSL locking hooks, if this is the last SSL
1580+
* connection, which means we must wait to call it until after all
1581+
* SSL calls have been made, otherwise we can end up with a race
1582+
* condition and possible deadlocks.
1583+
*
1584+
* See comments above destroy_ssl_system().
1585+
*/
1586+
if (destroy_needed)
1587+
pqsecure_destroy();
15681588
}
15691589

15701590
/*

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp