CVE-2023-53578

An uninitialized memory access flaw was found in the Linux kernel's QRTR (Qualcomm IPC Router) protocol in the transmit resume handling. When processing RESUME_TX messages, if the packet size is smaller than the expected control structure, the qrtr_tx_resume function reads uninitialized memory from the skb buffer. This can lead to unpredictable behavior, kernel warnings from KMSAN (Kernel Memory Sanitizer), and potential crashes, causing denial of service.

QRTR is a message-based IPC mechanism used in Qualcomm SoCs to communicate between processors and subsystems. The protocol uses control messages for flow control, including QRTR_TYPE_RESUME_TX packets that signal readiness to receive more data. The qrtr_tx_resume function expects these packets to contain at least a full qrtr_ctrl_pkt structure and reads fields from that structure. Meanwhile, qrtr_endpoint_post allocates an skb of size 'size' (from the received message) and sets skb->len to match. When a malformed or crafted message arrives with type QRTR_TYPE_RESUME_TX but size less than sizeof(struct qrtr_ctrl_pkt), the allocated skb doesn't contain enough initialized data. When qrtr_tx_resume tries to access fields of the control packet, it reads beyond the initialized portion into whatever random data happened to be in that memory.

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.