From 7720654b4842bcdfeb64bc002f6186041849e1e7 Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Mon, 25 May 2026 05:28:29 -0400 Subject: [PATCH] thunderbolt: Limit XDomain response copy to actual frame size commit 4db2bd2ed4785dbadaeeab9f4e346b21ac5fb8eb upstream. tb_xdomain_copy() copies req->response_size bytes from the received packet buffer regardless of the actual frame size. When a short response arrives, this reads past the valid frame data in the DMA pool buffer into stale contents from previous transactions. Use the minimum of frame size and expected response size for the copy length. Fixes: cdae7c07e3e3 ("thunderbolt: Add support for XDomain properties") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Mika Westerberg Signed-off-by: Greg Kroah-Hartman --- drivers/thunderbolt/xdomain.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c index fd50713ef798..df5e40c6876c 100644 --- a/drivers/thunderbolt/xdomain.c +++ b/drivers/thunderbolt/xdomain.c @@ -96,7 +96,9 @@ static bool tb_xdomain_match(const struct tb_cfg_request *req, static bool tb_xdomain_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg) { - memcpy(req->response, pkg->buffer, req->response_size); + size_t len = min_t(size_t, pkg->frame.size, req->response_size); + + memcpy(req->response, pkg->buffer, len); req->result.err = 0; return true; }