BUG/MINOR: ocsp: Crash when updating CA during ocsp updates

If an ocsp response is set to be updated automatically and some
certificate or CA updates are performed on the CLI, if the CLI update
happens while the OCSP response is being updated and is then detached
from the udapte tree, it might be wrongly inserted into the update tree
in 'ssl_sock_load_ocsp', and then reinserted when the update finishes.

The update tree then gets corrupted and we could end up crashing when
accessing other nodes in the ocsp response update tree.

This patch must be backported up to 2.8.
This patch fixes GitHub #3100.

diff --git a/include/haproxy/ssl_ocsp.h b/include/haproxy/ssl_ocsp.h
index e7828b6f0f87a462ab25f7ebc03711a28801e332..c7526bf11f38dd3f6b0ad4505cacfef60916394d 100644 (file)
--- a/include/haproxy/ssl_ocsp.h
+++ b/include/haproxy/ssl_ocsp.h
@@ -53,7 +53,7 @@ int ssl_ocsp_check_response(STACK_OF(X509) *chain, X509 *issuer,
 int ssl_create_ocsp_update_task(char **err);
 void ssl_destroy_ocsp_update_task(void);
 
-int ssl_ocsp_update_insert(struct certificate_ocsp *ocsp);
+int ssl_ocsp_update_insert(struct certificate_ocsp *ocsp, int needs_locking);
 
 int ocsp_update_init(void *value, char *buf, struct ckch_data *d, int cli, const char *filename, int linenum, char **err);
 

diff --git a/src/ssl_ocsp.c b/src/ssl_ocsp.c
index c2fe8d105dc948aa45644c8661bed4eee519e8df..52a245a659387f22ae9b1b94bfae05d4543bce9a 100644 (file)
--- a/src/ssl_ocsp.c
+++ b/src/ssl_ocsp.c
@@ -1048,7 +1048,7 @@ static inline void ssl_ocsp_set_next_update(struct certificate_ocsp *ocsp)
  * defined in order to avoid updating too often responses that have a really
  * short expire time or even no 'Next Update' at all.
  */
-int ssl_ocsp_update_insert(struct certificate_ocsp *ocsp)
+int ssl_ocsp_update_insert(struct certificate_ocsp *ocsp, int needs_locking)
 {
        /* Set next_update based on current time and the various OCSP
         * minimum/maximum update times.
@@ -1057,14 +1057,16 @@ int ssl_ocsp_update_insert(struct certificate_ocsp *ocsp)
 
        ocsp->fail_count = 0;
 
-       HA_SPIN_LOCK(OCSP_LOCK, &ocsp_tree_lock);
+       if (needs_locking)
+               HA_SPIN_LOCK(OCSP_LOCK, &ocsp_tree_lock);
        ocsp->updating = 0;
        /* An entry with update_once set to 1 was only supposed to be updated
         * once, it does not need to be reinserted into the update tree.
         */
        if (!ocsp->update_once)
                eb64_insert(&ocsp_update_tree, &ocsp->next_update);
-       HA_SPIN_UNLOCK(OCSP_LOCK, &ocsp_tree_lock);
+       if (needs_locking)
+               HA_SPIN_UNLOCK(OCSP_LOCK, &ocsp_tree_lock);
 
        return 0;
 }
@@ -1292,7 +1294,7 @@ static struct task *ssl_ocsp_update_responses(struct task *task, void *context,
                        ssl_ocsp_send_log();
 
                        /* Reinsert the entry into the update list so that it can be updated later */
-                       ssl_ocsp_update_insert(ocsp);
+                       ssl_ocsp_update_insert(ocsp, 0);
                        /* Release the reference kept on the updated ocsp response. */
                        ssl_sock_free_ocsp_instance(ctx->cur_ocsp);
                        ctx->cur_ocsp = NULL;

diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index ecaf24ee955ce7b7e5596bb9f1c63c77180000b3..6dce3cb98e4fb266bf403c56bcbfcdb7cdf9c3b7 100644 (file)
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -1499,7 +1499,7 @@ static int ssl_sock_load_ocsp(const char *path, SSL_CTX *ctx, struct ckch_store
                memcpy(iocsp->path, path, path_len + 1);
 
                if (enable_auto_update) {
-                       ssl_ocsp_update_insert(iocsp);
+                       ssl_ocsp_update_insert(iocsp, 1);
                        /* If we are during init the update task is not
                         * scheduled yet so a wakeup won't do anything.
                         * Otherwise, if the OCSP was added through the CLI, we
@@ -1517,18 +1517,28 @@ static int ssl_sock_load_ocsp(const char *path, SSL_CTX *ctx, struct ckch_store
                 * prior to the activation of the ocsp auto update and in such a
                 * case we must "force" insertion in the auto update tree.
                 */
+               HA_SPIN_LOCK(OCSP_LOCK, &ocsp_tree_lock);
                if (iocsp->next_update.node.leaf_p == NULL) {
-                       ssl_ocsp_update_insert(iocsp);
-                       /* If we are during init the update task is not
-                        * scheduled yet so a wakeup won't do anything.
-                        * Otherwise, if the OCSP was added through the CLI, we
-                        * wake the task up to manage the case of a new entry
-                        * that needs to be updated before the previous first
-                        * entry.
+                       /* We might be facing an entry that is currently being
+                        * updated, which can take some time (especially if the
+                        * ocsp responder is unreachable).
+                        * The entry will be reinserted by the update task, it
+                        * mustn't be reinserted here.
                         */
-                       if (ocsp_update_task)
-                               task_wakeup(ocsp_update_task, TASK_WOKEN_MSG);
+                       if (!iocsp->updating) {
+                               ssl_ocsp_update_insert(iocsp, 0);
+                               /* If we are during init the update task is not
+                                * scheduled yet so a wakeup won't do anything.
+                                * Otherwise, if the OCSP was added through the CLI, we
+                                * wake the task up to manage the case of a new entry
+                                * that needs to be updated before the previous first
+                                * entry.
+                                */
+                               if (ocsp_update_task)
+                                       task_wakeup(ocsp_update_task, TASK_WOKEN_MSG);
+                       }
                }
+               HA_SPIN_UNLOCK(OCSP_LOCK, &ocsp_tree_lock);
        }
 
 out: