From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 31 Oct 2023 11:12:02 +0000 (+0100)
Subject: 5.4-stable patches
X-Git-Tag: v6.1.61~33
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=69a3beb719e9c091c708b4fc6590c20acdace39b;p=thirdparty%2Fkernel%2Fstable-queue.git

5.4-stable patches

added patches:
	drm-dp_mst-fix-null-deref-in-get_mst_branch_device_by_guid_helper.patch
---

diff --git a/queue-5.4/drm-dp_mst-fix-null-deref-in-get_mst_branch_device_by_guid_helper.patch b/queue-5.4/drm-dp_mst-fix-null-deref-in-get_mst_branch_device_by_guid_helper.patch
new file mode 100644
index 00000000000..5af506e9d29
--- /dev/null
+++ b/queue-5.4/drm-dp_mst-fix-null-deref-in-get_mst_branch_device_by_guid_helper.patch
@@ -0,0 +1,67 @@
+From 3d887d512494d678b17c57b835c32f4e48d34f26 Mon Sep 17 00:00:00 2001
+From: Lukasz Majczak <lma@semihalf.com>
+Date: Fri, 22 Sep 2023 08:34:10 +0200
+Subject: drm/dp_mst: Fix NULL deref in get_mst_branch_device_by_guid_helper()
+
+From: Lukasz Majczak <lma@semihalf.com>
+
+commit 3d887d512494d678b17c57b835c32f4e48d34f26 upstream.
+
+As drm_dp_get_mst_branch_device_by_guid() is called from
+drm_dp_get_mst_branch_device_by_guid(), mstb parameter has to be checked,
+otherwise NULL dereference may occur in the call to
+the memcpy() and cause following:
+
+[12579.365869] BUG: kernel NULL pointer dereference, address: 0000000000000049
+[12579.365878] #PF: supervisor read access in kernel mode
+[12579.365880] #PF: error_code(0x0000) - not-present page
+[12579.365882] PGD 0 P4D 0
+[12579.365887] Oops: 0000 [#1] PREEMPT SMP NOPTI
+...
+[12579.365895] Workqueue: events_long drm_dp_mst_up_req_work
+[12579.365899] RIP: 0010:memcmp+0xb/0x29
+[12579.365921] Call Trace:
+[12579.365927] get_mst_branch_device_by_guid_helper+0x22/0x64
+[12579.365930] drm_dp_mst_up_req_work+0x137/0x416
+[12579.365933] process_one_work+0x1d0/0x419
+[12579.365935] worker_thread+0x11a/0x289
+[12579.365938] kthread+0x13e/0x14f
+[12579.365941] ? process_one_work+0x419/0x419
+[12579.365943] ? kthread_blkcg+0x31/0x31
+[12579.365946] ret_from_fork+0x1f/0x30
+
+As get_mst_branch_device_by_guid_helper() is recursive, moving condition
+to the first line allow to remove a similar one for step over of NULL elements
+inside a loop.
+
+Fixes: 5e93b8208d3c ("drm/dp/mst: move GUID storage from mgr, port to only mst branch")
+Cc: <stable@vger.kernel.org> # 4.14+
+Signed-off-by: Lukasz Majczak <lma@semihalf.com>
+Reviewed-by: Radoslaw Biernacki <rad@chromium.org>
+Signed-off-by: Manasi Navare <navaremanasi@chromium.org>
+Link: https://patchwork.freedesktop.org/patch/msgid/20230922063410.23626-1-lma@semihalf.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/gpu/drm/drm_dp_mst_topology.c |    6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+--- a/drivers/gpu/drm/drm_dp_mst_topology.c
++++ b/drivers/gpu/drm/drm_dp_mst_topology.c
+@@ -1806,14 +1806,14 @@ static struct drm_dp_mst_branch *get_mst
+ 	struct drm_dp_mst_branch *found_mstb;
+ 	struct drm_dp_mst_port *port;
+ 
++	if (!mstb)
++		return NULL;
++
+ 	if (memcmp(mstb->guid, guid, 16) == 0)
+ 		return mstb;
+ 
+ 
+ 	list_for_each_entry(port, &mstb->ports, next) {
+-		if (!port->mstb)
+-			continue;
+-
+ 		found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
+ 
+ 		if (found_mstb)
diff --git a/queue-5.4/series b/queue-5.4/series
index 23be6d60122..4616cfcfc29 100644
--- a/queue-5.4/series
+++ b/queue-5.4/series
@@ -35,3 +35,4 @@ acpica-add-support-for-madt-online-enabled-bit.patch
 x86-acpi-don-t-add-cpus-that-are-not-online-capable.patch
 x86-acpi-boot-use-fadt-version-to-check-support-for-.patch
 x86-i8259-skip-probing-when-acpi-madt-advertises-pca.patch
+drm-dp_mst-fix-null-deref-in-get_mst_branch_device_by_guid_helper.patch