FAILED: patch "[PATCH] thunderbolt: Validate XDomain request packet size before type" failed to apply to 5.10-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x a504b9f2797b739e0304d537e8aa4ce883ecce39
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026061520-civic-shiny-9fb0@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a504b9f2797b739e0304d537e8aa4ce883ecce39 Mon Sep 17 00:00:00 2001
From: Michael Bommarito <michael.bommarito@gmail.com>
Date: Mon, 25 May 2026 05:28:28 -0400
Subject: [PATCH] thunderbolt: Validate XDomain request packet size before type
 cast

tb_xdp_handle_request() casts the received packet buffer to
protocol-specific structs without verifying that the allocation
is large enough for the target type.  A peer can send a minimal
XDomain packet that passes the generic header length check but is
shorter than the struct accessed after the cast, causing out-of-
bounds reads from the kmemdup allocation.

Plumb the packet length through xdomain_request_work and validate
it against the expected struct size before each cast.

Fixes: 8e1de7042596 ("thunderbolt: Add support for XDomain lane bonding")
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 <michael.bommarito@gmail.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index 4099419c7479..9d54e3ccc827 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -55,6 +55,7 @@ static const char * const state_names[] = {
 struct xdomain_request_work {
 	struct work_struct work;
 	struct tb_xdp_header *pkg;
+	size_t pkg_len;
 	struct tb *tb;
 };
 
@@ -733,6 +734,7 @@ static void tb_xdp_handle_request(struct work_struct *work)
 	struct xdomain_request_work *xw = container_of(work, typeof(*xw), work);
 	const struct tb_xdp_header *pkg = xw->pkg;
 	const struct tb_xdomain_header *xhdr = &pkg->xd_hdr;
+	size_t pkg_len = xw->pkg_len;
 	struct tb *tb = xw->tb;
 	struct tb_ctl *ctl = tb->ctl;
 	struct tb_xdomain *xd;
@@ -764,7 +766,7 @@ static void tb_xdp_handle_request(struct work_struct *work)
 	switch (pkg->type) {
 	case PROPERTIES_REQUEST:
 		tb_dbg(tb, "%llx: received XDomain properties request\n", route);
-		if (xd) {
+		if (xd && pkg_len >= sizeof(struct tb_xdp_properties)) {
 			ret = tb_xdp_properties_response(tb, ctl, xd, sequence,
 				(const struct tb_xdp_properties *)pkg);
 		}
@@ -818,7 +820,8 @@ static void tb_xdp_handle_request(struct work_struct *work)
 		tb_dbg(tb, "%llx: received XDomain link state change request\n",
 		       route);
 
-		if (xd && xd->state == XDOMAIN_STATE_BONDING_UUID_HIGH) {
+		if (xd && xd->state == XDOMAIN_STATE_BONDING_UUID_HIGH &&
+		    pkg_len >= sizeof(struct tb_xdp_link_state_change)) {
 			const struct tb_xdp_link_state_change *lsc =
 				(const struct tb_xdp_link_state_change *)pkg;
 
@@ -870,6 +873,7 @@ tb_xdp_schedule_request(struct tb *tb, const struct tb_xdp_header *hdr,
 		kfree(xw);
 		return false;
 	}
+	xw->pkg_len = size;
 	xw->tb = tb_domain_get(tb);
 
 	schedule_work(&xw->work);