From fac9275820a32748144fe08f8b92493bb85b63e0 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Wed, 15 Jul 2026 08:51:26 -0700 Subject: [PATCH] cxl: Deny Features commands on the RAW mailbox path The RAW mailbox command path allows user to issue arbitrary opcodes to the device. The FWCTL interface was introduced to support the CXL Features commands where access control is provided depends on what the CEL indicates. Add the Features commands to cxl_disabled_raw_commands[] to ensure that all Features commands are only accessible through the FWCTL interface. The cxl_raw_allow_all debugfs override knob bypasses the disabled list if the user is aware of the risks and wants to use the RAW path for Features commands. Reviewed-by: Alison Schofield Link: https://patch.msgid.link/20260715155126.1629178-1-dave.jiang@intel.com Signed-off-by: Dave Jiang --- drivers/cxl/core/mbox.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index 7c6c5b7450a5..6dea70a1ff95 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -91,6 +91,10 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = { * * CXL_MBOX_OP_[GET_,INJECT_,CLEAR_]POISON: These commands require kernel * driver orchestration for safety. + * + * CXL_MBOX_OP_[GET_SUPPORTED_FEATURES,GET_FEATURE,SET_FEATURE]: Features are + * accessed through the fwctl ABI, which applies scope-based access control. + * The RAW path would bypass those checks, so it is not permitted here. */ static u16 cxl_disabled_raw_commands[] = { CXL_MBOX_OP_ACTIVATE_FW, @@ -102,6 +106,9 @@ static u16 cxl_disabled_raw_commands[] = { CXL_MBOX_OP_GET_POISON, CXL_MBOX_OP_INJECT_POISON, CXL_MBOX_OP_CLEAR_POISON, + CXL_MBOX_OP_GET_SUPPORTED_FEATURES, + CXL_MBOX_OP_GET_FEATURE, + CXL_MBOX_OP_SET_FEATURE, }; /*