Messages in this thread | | | Date | Thu, 19 May 2022 09:44:25 +0800 | Subject | Re: [PATCH] media: dvb_vb2: fix possible out of bound access | From | Hangyu Hua <> |
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On 2022/5/18 18:44, Hans Verkuil wrote: > Hi Hangyu, > > It appears this patch fell through the cracks. It's certainly useful to > have. > > On 3/24/22 09:01, Hangyu Hua wrote: >> 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. >> >> Signed-off-by: Hangyu Hua <hbh25y@gmail.com> >> --- >> drivers/media/dvb-core/dvb_vb2.c | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c >> index a1bd6d9c9223..f410800b92e7 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(q, 1, "buffer index out of range\n"); > > However, this patch doesn't compile: dprintk in this source doesn't > have a 'q' argument!
Oops, i will fix this out.
> >> + return -EINVAL; >> + } >> vb2_core_querybuf(&ctx->vb_q, b->index, b); >> dprintk(3, "[%s] index=%d\n", ctx->name, b->index); > > Also, to help debugging it prefixes the warnings with the ctx-name. > > Can you post a v2 of this patch? > > Regards, > > Hans
I will send a v2 later.
Thanks, Hangyu
> >> 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(q, 1, "buffer index out of range\n"); >> + 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,
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