From 261c1fe3327ad24508f54552c6366e3e4db82c15 Mon Sep 17 00:00:00 2001 From: Doruk Tan Ozturk Date: Mon, 13 Jul 2026 19:30:28 +0200 Subject: [PATCH] accel/amdxdna: reject user command submission without a command BO amdxdna_drm_submit_execbuf() passes the user-supplied command BO handle straight into amdxdna_cmd_submit() with drv_cmd == NULL. When the handle is AMDXDNA_INVALID_BO_HANDLE (0), the block that fetches job->cmd_bo is skipped, leaving it NULL, and no check rejects it on the user path (the !job->cmd_bo guard lives inside the != INVALID branch). The job is then armed and pushed to the DRM scheduler. aie2_sched_job_run() takes the drv_cmd == NULL path and calls amdxdna_cmd_set_state(job->cmd_bo) -> amdxdna_gem_vmap(NULL) -> to_gobj(NULL)->dev, a NULL pointer dereference in the drm_sched 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 AMDXDNA_EXEC_CMD ioctl (cmd_handles = 0). Only internal driver commands (SYNC_DEBUG_BO / ATTACH_DEBUG_BO) legitimately pass AMDXDNA_INVALID_BO_HANDLE, and they always set drv_cmd. Reject the invalid handle for user submissions (drv_cmd == NULL) at the submit choke point so every user path is covered. Fixes: aac243092b70 ("accel/amdxdna: Add command execution") Cc: stable@vger.kernel.org Found by 0sec automated security-research tooling (https://0sec.ai). Assisted-by: 0sec:claude-opus-4-8 Signed-off-by: Doruk Tan Ozturk Reviewed-by: Lizhi Hou Signed-off-by: Lizhi Hou Link: https://patch.msgid.link/20260713173030.87541-2-doruk@0sec.ai --- drivers/accel/amdxdna/amdxdna_ctx.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/accel/amdxdna/amdxdna_ctx.c b/drivers/accel/amdxdna/amdxdna_ctx.c index 8f8df9d04ec5..a5c8c2c4de6d 100644 --- a/drivers/accel/amdxdna/amdxdna_ctx.c +++ b/drivers/accel/amdxdna/amdxdna_ctx.c @@ -603,6 +603,16 @@ int amdxdna_cmd_submit(struct amdxdna_client *client, ret = -EINVAL; goto free_job; } + } else if (!drv_cmd) { + /* + * Only internal driver commands (drv_cmd != NULL) may omit a + * command BO. A user command submission with the invalid handle + * would leave job->cmd_bo NULL and later fault when the scheduler + * dereferences it in amdxdna_cmd_set_state(). + */ + XDNA_DBG(xdna, "Command BO handle required for user submission"); + ret = -EINVAL; + goto free_job; } ret = amdxdna_arg_bos_lookup(client, job, arg_bo_hdls, arg_bo_cnt);