CVE-2022-50475

A NULL pointer dereference flaw was found in the Linux kernel RDMA core's sysfs handling. A local user with access to InfiniBand sysfs nodes can read sysfs attributes while an InfiniBand port is being removed, causing the kernel to dereference a NULL ib_port pointer when the port structure has been freed but sysfs access is still possible, which results in a NULL pointer dereference and denial of service through kernel crash.

The issue arises because sysfs attribute handlers fail to validate that the ib_port pointer is non-NULL before dereferencing it. When userspace accesses sysfs nodes under /sys/class/infiniband/ (such as port state, capabilities, or statistics), the kernel retrieves the associated port structure. During device removal or port state changes, the port structure can be freed while sysfs nodes still exist. If a sysfs read occurs during or after this removal, the code dereferences a NULL or freed ib_port pointer, causing a kernel crash. This can be triggered by simply reading sysfs attributes while removing or reconfiguring InfiniBand devices.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.