Revert "misc: fastrpc: Restrict untrusted app to attach to privileged PD"

This reverts commit bab2f5e8fd5d2f759db26b78d9db57412888f187.

Joel reported that this commit breaks userspace and stops sensors in
SDM845 from working. Also breaks other qcom SoC devices running postmarketOS.

Cc: stable <stable@kernel.org>
Cc: Ekansh Gupta <quic_ekangupt@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reported-by: Joel Selvaraj <joelselvaraj.oss@gmail.com>
Link: https://lore.kernel.org/r/9a9f5646-a554-4b65-8122-d212bb665c81@umsystem.edu
Signed-off-by: Griffin Kroah-Hartman <griffin@kroah.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Fixes: bab2f5e8fd5d ("misc: fastrpc: Restrict untrusted app to attach to privileged PD")
Link: https://lore.kernel.org/r/20240815094920.8242-1-griffin@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 5204fda51da3fc497b62c51de6c7d74987339f40..339d126414d4bf842d08c593e15bd6a3954bbf38 100644 (file)
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -2085,16 +2085,6 @@ err_invoke:
        return err;
 }
 
-static int is_attach_rejected(struct fastrpc_user *fl)
-{
-       /* Check if the device node is non-secure */
-       if (!fl->is_secure_dev) {
-               dev_dbg(&fl->cctx->rpdev->dev, "untrusted app trying to attach to privileged DSP PD\n");
-               return -EACCES;
-       }
-       return 0;
-}
-
 static long fastrpc_device_ioctl(struct file *file, unsigned int cmd,
                                 unsigned long arg)
 {
@@ -2107,19 +2097,13 @@ static long fastrpc_device_ioctl(struct file *file, unsigned int cmd,
                err = fastrpc_invoke(fl, argp);
                break;
        case FASTRPC_IOCTL_INIT_ATTACH:
-               err = is_attach_rejected(fl);
-               if (!err)
-                       err = fastrpc_init_attach(fl, ROOT_PD);
+               err = fastrpc_init_attach(fl, ROOT_PD);
                break;
        case FASTRPC_IOCTL_INIT_ATTACH_SNS:
-               err = is_attach_rejected(fl);
-               if (!err)
-                       err = fastrpc_init_attach(fl, SENSORS_PD);
+               err = fastrpc_init_attach(fl, SENSORS_PD);
                break;
        case FASTRPC_IOCTL_INIT_CREATE_STATIC:
-               err = is_attach_rejected(fl);
-               if (!err)
-                       err = fastrpc_init_create_static_process(fl, argp);
+               err = fastrpc_init_create_static_process(fl, argp);
                break;
        case FASTRPC_IOCTL_INIT_CREATE:
                err = fastrpc_init_create_process(fl, argp);

diff --git a/include/uapi/misc/fastrpc.h b/include/uapi/misc/fastrpc.h
index 91583690bddc5294e926d73b40d201f039474b28..f33d914d8f4699eddef9f9910ec2b30440c26e83 100644 (file)
--- a/include/uapi/misc/fastrpc.h
+++ b/include/uapi/misc/fastrpc.h
@@ -8,14 +8,11 @@
 #define FASTRPC_IOCTL_ALLOC_DMA_BUFF   _IOWR('R', 1, struct fastrpc_alloc_dma_buf)
 #define FASTRPC_IOCTL_FREE_DMA_BUFF    _IOWR('R', 2, __u32)
 #define FASTRPC_IOCTL_INVOKE           _IOWR('R', 3, struct fastrpc_invoke)
-/* This ioctl is only supported with secure device nodes */
 #define FASTRPC_IOCTL_INIT_ATTACH      _IO('R', 4)
 #define FASTRPC_IOCTL_INIT_CREATE      _IOWR('R', 5, struct fastrpc_init_create)
 #define FASTRPC_IOCTL_MMAP             _IOWR('R', 6, struct fastrpc_req_mmap)
 #define FASTRPC_IOCTL_MUNMAP           _IOWR('R', 7, struct fastrpc_req_munmap)
-/* This ioctl is only supported with secure device nodes */
 #define FASTRPC_IOCTL_INIT_ATTACH_SNS  _IO('R', 8)
-/* This ioctl is only supported with secure device nodes */
 #define FASTRPC_IOCTL_INIT_CREATE_STATIC _IOWR('R', 9, struct fastrpc_init_create_static)
 #define FASTRPC_IOCTL_MEM_MAP          _IOWR('R', 10, struct fastrpc_mem_map)
 #define FASTRPC_IOCTL_MEM_UNMAP                _IOWR('R', 11, struct fastrpc_mem_unmap)