cxl/features: Reject Get Feature count larger than the output buffer

Browse source

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.

Fixes: 5908f3ed6d ("cxl: Add support to handle user feature commands for get feature")
Reviewed-by: Kai-Heng Feng <kaihengf@nvidia.com>
Reviewed-by: Koba Ko <kobak@nvidia.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://patch.msgid.link/20260626104102.53892-2-icheng@nvidia.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

...

This commit is contained in:

Richard Cheng 2026-06-26 18:41:00 +08:00 • committed by Dave Jiang

parent a623128bc2

commit 4bf6bac375

1 changed files with 4 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

4

drivers/cxl/core/features.c

View file