FAILED: patch "[PATCH] media: dvb_vb2: fix possible out of bound access" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-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 <[email protected]>.

Possible dependencies:

37238699073e ("media: dvb_vb2: fix possible out of bound access") fd89e0bb6ebf ("media: videobuf2-core: integrate with media requests") 55028695c3bb ("media: vb2: drop VB2_BUF_STATE_PREPARED, use bool prepared/synced instead") db6e8d57e2cd ("media: vb2: store userspace data in vb2_v4l2_buffer") 0af4e80bf24a ("media: videobuf2-v4l2: replace if by switch in __fill_vb2_buffer()") 5f89ec80f1e0 ("media: videobuf2-v4l2: move __fill_v4l2_buffer() function")

thanks,

greg k-h

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

From 37238699073e7e93f05517e529661151173cd458 Mon Sep 17 00:00:00 2001
From: Hangyu Hua <[email protected]>
Date: Thu, 19 May 2022 03:17:43 +0100
Subject: [PATCH] media: dvb_vb2: fix possible out of bound access

vb2_core_qbuf and vb2_core_querybuf don't check the range of b->index controlled by the user.

Fix this by adding range checking code before using them.

index a1bd6d9c9223..909df82fed33 100644
@@ -354,6 +354,12 @@ int dvb_vb2_reqbufs(struct dvb_vb2_ctx *ctx, struct dmx_requestbuffers *req)
 
 int dvb_vb2_querybuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b)
 {
+	struct vb2_queue *q = &ctx->vb_q;
+
+	if (b->index >= q->num_buffers) {
+		dprintk(1, "[%s] buffer index out of range\n", ctx->name);
+		return -EINVAL;
+	}
 	vb2_core_querybuf(&ctx->vb_q, b->index, b);
 	dprintk(3, "[%s] index=%d\n", ctx->name, b->index);
 	return 0;

@@ -378,8 +384,13 @@ int dvb_vb2_expbuf(struct dvb_vb2_ctx *ctx, struct dmx_exportbuffer *exp)
 
 int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b)
 {
+	struct vb2_queue *q = &ctx->vb_q;
 	int ret;
 
+	if (b->index >= q->num_buffers) {
+		dprintk(1, "[%s] buffer index out of range\n", ctx->name);
+		return -EINVAL;
+	}
 	ret = vb2_core_qbuf(&ctx->vb_q, b->index, b, NULL);
 	if (ret) {
 		dprintk(1, "[%s] index=%d errno=%d\n", ctx->name,