Fix double-free of EG(errors)/persistent_script->warnings on persist of already persisted file #19995
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arnaud-lb
reviewed
Sep 30, 2025
…of already persisted file Both processes race to compile warning_replay.inc. Whichever is first will get to persist the script. The loser will use the script that is already persisted, and the script that was just compiled is freed. However, EG(errors) and persistent_script->warnings still refer to the same allocation, and EG(errors) becomes a dangling pointer. To solve this, we simply don't free warnings from free_persistent_script() anymore to maintain exclusive ownership for EG(errors). Furthermore, we need to adjust a call to zend_emit_recorded_errors() that would previously use EG(errors), even when persistent_script has been swapped out. Fixes phpGH-19984
arnaud-lb
approved these changes
Sep 30, 2025
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Both processes race to compile warning_replay.inc. Whichever is first will get to persist the script. The loser will use the script that is already persisted, and the script that was just compiled is freed.
However, EG(errors) and persistent_script->warnings still refer to the same allocation, and EG(errors) becomes a dangling pointer. To solve this, we simply set EG(errors) and EG(num_errors) to NULL and 0, respectively.
Furthermore, we need to adjust some calls to zend_emit_recorded_errors() that would previously use EG(errors), even when persistent_script has been swapped out.
Fixes GH-19984