On 30/05/2024 11:20, Ekansh Gupta wrote:
Untrusted application with access to only non-secure fastrpc device
node can attach to root_pd or static PDs if it can make the respective
init request. This can cause problems as the untrusted application
can send bad requests to root_pd or static PDs. Add changes to reject
attach to privileged PDs if the request is being made using non-secure
fastrpc device node.
Fixes: 0871561055e6 ("misc: fastrpc: Add support for audiopd")
Cc: stable <stable@xxxxxxxxxx>
Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
---
drivers/misc/fastrpc.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index d9d9f889e39e..73fa0e536cf9 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -1344,6 +1344,11 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
} inbuf;
u32 sc;
+ if (!fl->is_secure_dev) {
+ dev_dbg(&fl->cctx->rpdev->dev, "untrusted app trying to attach to privileged DSP PD\n");
+ return -EACCES;
+ }
Please move these checks to fastrpc_device_ioctl which makes it clear
that these are only supported with secure device nodes.
I would also prefer this to be documented in the the uapi headers.
--srini
+
args = kcalloc(FASTRPC_CREATE_STATIC_PROCESS_NARGS, sizeof(*args), GFP_KERNEL);
if (!args)
return -ENOMEM;
@@ -1769,6 +1774,11 @@ static int fastrpc_init_attach(struct fastrpc_user *fl, int pd)
int tgid = fl->tgid;
u32 sc;
+ if (!fl->is_secure_dev) {
+ dev_dbg(&fl->cctx->rpdev->dev, "untrusted app trying to attach to privileged DSP PD\n");
+ return -EACCES;
+ }
+
args[0].ptr = (u64)(uintptr_t) &tgid;
args[0].length = sizeof(tgid);
args[0].fd = -1;
