CVE-2024-50274

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

idpf: avoid vport access in idpf_get_link_ksettings

When the device control plane is removed or the platform running device control plane is rebooted, a reset is detected on the driver. On driver reset, it releases the resources and waits for the reset to complete. If the reset fails, it takes the error path and releases the vport lock. At this time if the monitoring tools tries to access link settings, it call traces for accessing released vport pointer.

To avoid it, move link_speed_mbps to netdev_priv structure which removes the dependency on vport pointer and the vport lock in idpf_get_link_ksettings. Also use netif_carrier_ok() to check the link status and adjust the offsetof to use link_up instead of link_speed_mbps.

Weakness

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

Affected Software

Extended Description

The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code, depending on the instantiation and timing of the flaw. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common and sometimes overlapping causes:

In this scenario, the memory in question is allocated to another pointer validly at some point after it has been freed. The original pointer to the freed memory is used again and points to somewhere within the new allocation. As the data is changed, it corrupts the validly used memory; this induces undefined behavior in the process. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.

Potential Mitigations

References

• https://git.kernel.org/stable/c/81d2fb4c7c18a3b36ba3e00b9d5b753107472d75
• https://git.kernel.org/stable/c/fa4d906ad0fb63a980a1d586a061c78ea1a345ba