CVE-2026-72091: accel/amdxdna: reject user command submission without a command BO

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

accel/amdxdna: reject user command submission without a command BO

amdxdnadrmsubmitexecbuf() passes the user-supplied command BO handle straight into amdxdnacmdsubmit() with drvcmd == NULL. When the handle is AMDXDNAINVALIDBOHANDLE (0), the block that fetches job->cmdbo is skipped, leaving it NULL, and no check rejects it on the user path (the !job->cmdbo guard lives inside the != INVALID branch).

The job is then armed and pushed to the DRM scheduler. aie2schedjobrun() takes the drvcmd == NULL path and calls amdxdnacmdsetstate(job->cmdbo) -> amdxdnagemvmap(NULL) -> togobj(NULL)->dev, a NULL pointer dereference in the drmsched worker. A process with access to the accel node on a system with a probed AMD NPU can trigger a kernel oops with a single AMDXDNAEXECCMD ioctl (cmdhandles = 0).

Only internal driver commands (SYNCDEBUGBO / ATTACHDEBUGBO) legitimately pass AMDXDNAINVALIDBOHANDLE, and they always set drvcmd. Reject the invalid handle for user submissions (drvcmd == NULL) at the submit choke point so every user path is covered.

Found by 0sec automated security-research tooling (https://0sec.ai).