CVE-2024-44964 Information

Description

In the Linux kernel the following vulnerability has been resolved:

idpf: fix memory leaks and crashes while performing a soft reset

The second tagged commit introduced a UAF as it removed restoring q_vector->vport pointers after reinitializating the structures. This is due to that all queue allocation functions are performed here with the new temporary vport structure and those functions rewrite the backpointers to the vport. Then this new struct is freed and the pointers start leading to nowhere.

But generally speaking the current logic is very fragile. It claims to be more reliable when the system is low on memory but in fact it consumes two times more memory as at the moment of running this function there are two vports allocated with their queues and vectors. Moreover it claims to prevent the driver from running into ad state\nbut in fact any error during the rebuild leaves the old vport in the partially allocated state. Finally if the interface is down when the function is called it always allocates a new queue set but when the user decides to enable the interface later on vport_open() allocates them once again IOW there’s a clear memory leak here.

Just don’t allocate a new queue set when performing a reset that solves crashes and memory leaks. Readd the old queue number and reopen the interface on rollback - that solves limbo states when the device is left disabled and/or without HW queues enabled.

Reference

https://git.kernel.org/stable/c/6b289f8d91537ec1e4f9c7b38b31b90d93b1419b https://git.kernel.org/stable/c/f01032a2ca099ec8d619aaa916c3762aa62495df