CVE-2026-23322

In the Linux kernel, the following vulnerability has been resolved:

ipmi: Fix use-after-free and list corruption on sender error

The analysis from Breno:

When the SMI sender returns an error, smi_work() delivers an error response but then jumps back to restart without cleaning up properly:

1. intf->curr_msg is not cleared, so no new message is pulled
2. newmsg still points to the message, causing sender() to be called again with the same message
3. If sender() fails again, delivererrresponse() is called with the same recv_msg that was already queued for delivery

This causes listadd corruption ("listadd double add") because the recvmsg is added to the usermsgs list twice. Subsequently, the corrupted list leads to use-after-free when the memory is freed and reused, and eventually a NULL pointer dereference when accessing recv_msg->done.

The buggy sequence:

sender() fails -> delivererrresponse(recvmsg) // recvmsg queued for delivery -> goto restart // currmsg not cleared! sender() fails again (same message!) -> delivererrresponse(recvmsg) // tries to queue same recv_msg -> LIST CORRUPTION

Fix this by freeing the message and setting it to NULL on a send error. Also, always free the newmsg on a send error, otherwise it will leak.