head_errlog: fix use-after-free

In the commit of the head_errlog feature we introduced a bug in
dsl_dataset_promote_sync(): we may dereference origin_head and hds, both
dereferencing ddpa after calling promote_sync() on ddpa.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chunwei Chen <david.chen@nutanix.com>
Reviewed-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: George Amanakis <gamanakis@gmail.com>
Closes 
Closes 
This commit is contained in:
George Amanakis 2024-07-15 18:05:42 +02:00 committed by GitHub
parent f7d8b13336
commit c87cb22ba9
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1 changed files with 5 additions and 2 deletions
module/zfs

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@ -3712,16 +3712,19 @@ dsl_dataset_promote_sync(void *arg, dmu_tx_t *tx)
spa_history_log_internal_ds(hds, "promote", tx, " ");
dsl_dir_rele(odd, FTAG);
promote_rele(ddpa, FTAG);
/*
* Transfer common error blocks from old head to new head.
* Transfer common error blocks from old head to new head, before
* calling promote_rele() on ddpa since we need to dereference
* origin_head and hds.
*/
if (spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_HEAD_ERRLOG)) {
uint64_t old_head = origin_head->ds_object;
uint64_t new_head = hds->ds_object;
spa_swap_errlog(dp->dp_spa, new_head, old_head, tx);
}
promote_rele(ddpa, FTAG);
}
/*