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 stable@vger.kernel.org.

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 hbh25y@gmail.com 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.

Fixes: 57868acc369a ("media: videobuf2: Add new uAPI for DVB streaming I/O") Signed-off-by: Hangyu Hua hbh25y@gmail.com Reviewed-by: Sergey Senozhatsky senozhatsky@chromium.org Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org

diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c index a1bd6d9c9223..909df82fed33 100644 --- a/drivers/media/dvb-core/dvb_vb2.c +++ b/drivers/media/dvb-core/dvb_vb2.c @@ -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,