CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's handling of the CXL (Compute Express Link) framework, specifically in the `fwctl_cmd_rpc()` function, which fails to properly validate the user-controlled `op_size` against the allocated input buffer size. This oversight can lead to out-of-bounds memory access, potentially allowing an attacker to manipulate kernel memory, causing crashes or other undefined behavior. Organizations utilizing Linux systems with CXL support should prioritize addressing this vulnerability to mitigate the risk of exploitation.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: cxl/features: bound fwctl command payload to the input buffer fwctl_cmd_rpc() copies cmd->in_len bytes into inbuf = kvzalloc(cmd->in_len) and passes inbuf and in_len to ->fw_rpc(). The CXL callback cxlctl_fw_rpc() ignores in_len and never checks the user-controlled op_size against it. cxlctl_set_feature() bounds op_size only from below (op_size <= sizeof(feat_in->hdr)) and then reads op_size - sizeof(hdr) bytes from feat_in->feat_data via cxl_set_feature(). With a small in_len and a large op_size the first memcpy() already reads past the kvzalloc(in_len) buffer; the out-of-bounds bytes are placed in the mailbox payload and sent to the device, and a large enough op_size can walk into unmapped memory and oops the kernel. The Get paths pin op_size to a fixed size but likewise read the input struct without checking in_len. Reject, at the single dispatch point, any request whose fixed header plus op_size does not fit in the copied-in buffer. The lower-bound test guards the subtraction and ensures op_size was copied in before it is read.