Module CLIENT_CHANGE, Fix crash on free blocked client with DB!=0 (#11500)

In moduleFireServerEvent we change the real client DB to 0 on freeClient in case the event is REDISMODULE_EVENT_CLIENT_CHANGE.
It results in a crash if the client is blocked on a key on other than DB 0.

The DB change is not necessary even for module-client, as we set its DB to 0 on either createClient or moduleReleaseTempClient.

Co-authored-by: Madelyn Olson <34459052+madolson@users.noreply.github.com>
Co-authored-by: Binbin <binloveplay1314@qq.com>
(cherry picked from commit e4eb18b303)
This commit is contained in:
uriyage 2022-11-15 00:40:35 +02:00 committed by Oran Agra
parent abf83bc682
commit 7ad786db2e
2 changed files with 13 additions and 7 deletions

View File

@ -7974,7 +7974,6 @@ void moduleCallClusterReceivers(const char *sender_id, uint64_t module_id, uint8
if (r->module_id == module_id) {
RedisModuleCtx ctx;
moduleCreateContext(&ctx, r->module, REDISMODULE_CTX_TEMP_CLIENT);
selectDb(ctx.client, 0);
r->callback(&ctx,sender_id,type,payload,len);
moduleFreeContext(&ctx);
return;
@ -10787,11 +10786,6 @@ void moduleFireServerEvent(uint64_t eid, int subid, void *data) {
RedisModuleClientInfoV1 civ1;
RedisModuleReplicationInfoV1 riv1;
RedisModuleModuleChangeV1 mcv1;
/* Start at DB zero by default when calling the handler. It's
* up to the specific event setup to change it when it makes
* sense. For instance for FLUSHDB events we select the correct
* DB automatically. */
selectDb(ctx.client, 0);
/* Event specific context and data pointer setup. */
if (eid == REDISMODULE_EVENT_CLIENT_CHANGE) {
@ -11275,7 +11269,6 @@ int moduleLoad(const char *path, void **module_argv, int module_argc, int is_loa
}
RedisModuleCtx ctx;
moduleCreateContext(&ctx, NULL, REDISMODULE_CTX_TEMP_CLIENT); /* We pass NULL since we don't have a module yet. */
selectDb(ctx.client, 0);
if (onload((void*)&ctx,module_argv,module_argc) == REDISMODULE_ERR) {
serverLog(LL_WARNING,
"Module %s initialization failed. Module not loaded",path);

View File

@ -15,6 +15,19 @@ tags "modules" {
assert {[r hooks.event_count client-disconnected] > 1}
}
test {Test module client change event for blocked client} {
set rd [redis_deferring_client]
# select db other than 0
$rd select 1
# block on key
$rd brpop foo 0
# kill blocked client
r client kill skipme yes
# assert server is still up
assert_equal [r ping] PONG
$rd close
}
test {Test module cron hook} {
after 100
assert {[r hooks.event_count cron-loop] > 0}