High · published September 17, 2026
In the Linux kernel, the following vulnerability has been resolved:
cxl/features: Reject Get Feature count larger than the output buffer
cxlctl_get_feature() sizes its output buffer from the user's
fwctl_rpc.out_len, but the device is told to write
cxl_mbox_get_feat_in.count bytes into rpc_out->payload, which is a
separate user-controlled value. Nothing bounds count against out_len, so
a small out_len with a large count overflows the kvzalloc()'d buffer.
A heap OOB write reachable from FWCTL_RPC.
Reject requests where count exceeds the available payload room, before
allocating.