In the Linux kernel, the following vulnerability has been resolved:
espintcp: Fix race condition in espintcp_close()
This issue was discovered during a code audit.
After cancel_work_sync() is called from espintcp_close(), espintcp_tx_work() can still be scheduled from paths such as the Delayed ACK handler or ksoftirqd. As a result, the espintcp_tx_work() worker may dereference a freed espintcp ctx or sk.
The following is a simple race scenario:
cpu0 cpu1
espintcp_close() cancel_work_sync(&ctx->work); espintcp_write_space() schedule_work(&ctx->work);
To prevent this race condition, cancel_work_sync() is replaced with disable_work_sync().