[v3] misc: fastrpc: Refactor and add userspace buffer support

[PATCH v3 1/3] misc: fastrpc: Sanitize address logging and remove tabs

Posted by Ekansh Gupta 1 month, 1 week ago

Avoid printing raw addresses in driver logs by using %p for remote
buffer addresses. This reduces the risk of information leaks and
conforms to kernel logging guidelines. Remove tabs in dev_*
messages.

Fixes: 2419e55e532d ("misc: fastrpc: add mmap/unmap support")
Cc: stable@kernel.org
Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
---
 drivers/misc/fastrpc.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index ee652ef01534..408fe47e9db7 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -1830,13 +1830,13 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *
 	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
 				      &args[0]);
 	if (!err) {
-		dev_dbg(dev, "unmmap\tpt 0x%09lx OK\n", buf->raddr);
+		dev_dbg(dev, "unmap OK: raddr=%p\n", (void *)(unsigned long)buf->raddr);
 		spin_lock(&fl->lock);
 		list_del(&buf->node);
 		spin_unlock(&fl->lock);
 		fastrpc_buf_free(buf);
 	} else {
-		dev_err(dev, "unmmap\tpt 0x%09lx ERROR\n", buf->raddr);
+		dev_err(dev, "unmap error: raddr=%p\n", (void *)(unsigned long)buf->raddr);
 	}
 
 	return err;
@@ -1861,8 +1861,8 @@ static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp)
 	spin_unlock(&fl->lock);
 
 	if (!buf) {
-		dev_err(dev, "mmap\t\tpt 0x%09llx [len 0x%08llx] not in list\n",
-			req.vaddrout, req.size);
+		dev_err(dev, "buffer not found: addr=%p [len=0x%08llx]\n",
+			(void *)(unsigned long)req.vaddrout, req.size);
 		return -EINVAL;
 	}
 
@@ -1959,8 +1959,8 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
 		goto err_assign;
 	}
 
-	dev_dbg(dev, "mmap\t\tpt 0x%09lx OK [len 0x%08llx]\n",
-		buf->raddr, buf->size);
+	dev_dbg(dev, "mmap OK: raddr=%p [len=0x%08llx]\n",
+		(void *)(unsigned long)buf->raddr, buf->size);
 
 	return 0;
 
@@ -2006,7 +2006,8 @@ static int fastrpc_req_mem_unmap_impl(struct fastrpc_user *fl, struct fastrpc_me
 	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
 				      &args[0]);
 	if (err) {
-		dev_err(dev, "unmmap\tpt fd = %d, 0x%09llx error\n",  map->fd, map->raddr);
+		dev_err(dev, "unmap error: fd=%d, raddr=%p\n",
+			map->fd, (void *)(unsigned long)map->raddr);
 		return err;
 	}
 	fastrpc_map_put(map);
@@ -2074,8 +2075,8 @@ static int fastrpc_req_mem_map(struct fastrpc_user *fl, char __user *argp)
 	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MEM_MAP, 3, 1);
 	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc, &args[0]);
 	if (err) {
-		dev_err(dev, "mem mmap error, fd %d, vaddr %llx, size %lld\n",
-			req.fd, req.vaddrin, map->len);
+		dev_err(dev, "mem mmap error: fd=%d, vaddrin=%p, size=%lld\n",
+			req.fd, (void *)(unsigned long)req.vaddrin, map->len);
 		goto err_invoke;
 	}
 
-- 
2.34.1

Re: [PATCH v3 1/3] misc: fastrpc: Sanitize address logging and remove tabs

Posted by Konrad Dybcio 1 month, 1 week ago

On 12/30/25 12:02 PM, Ekansh Gupta wrote:
> Avoid printing raw addresses in driver logs by using %p for remote
> buffer addresses. This reduces the risk of information leaks and
> conforms to kernel logging guidelines. Remove tabs in dev_*
> messages.
> 
> Fixes: 2419e55e532d ("misc: fastrpc: add mmap/unmap support")
> Cc: stable@kernel.org
> Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
> ---
>  drivers/misc/fastrpc.c | 19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> index ee652ef01534..408fe47e9db7 100644
> --- a/drivers/misc/fastrpc.c
> +++ b/drivers/misc/fastrpc.c
> @@ -1830,13 +1830,13 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *
>  	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
>  				      &args[0]);
>  	if (!err) {
> -		dev_dbg(dev, "unmmap\tpt 0x%09lx OK\n", buf->raddr);
> +		dev_dbg(dev, "unmap OK: raddr=%p\n", (void *)(unsigned long)buf->raddr);

Would it be easier if we did away with the uintptr_t, since the protocol
seems to assume all addresses are u64s anyway?

Konrad

Re: [PATCH v3 1/3] misc: fastrpc: Sanitize address logging and remove tabs

Posted by Greg KH 1 month, 1 week ago

On Tue, Dec 30, 2025 at 02:23:55PM +0100, Konrad Dybcio wrote:
> On 12/30/25 12:02 PM, Ekansh Gupta wrote:
> > Avoid printing raw addresses in driver logs by using %p for remote
> > buffer addresses. This reduces the risk of information leaks and
> > conforms to kernel logging guidelines. Remove tabs in dev_*
> > messages.
> > 
> > Fixes: 2419e55e532d ("misc: fastrpc: add mmap/unmap support")
> > Cc: stable@kernel.org
> > Signed-off-by: Ekansh Gupta <ekansh.gupta@oss.qualcomm.com>
> > ---
> >  drivers/misc/fastrpc.c | 19 ++++++++++---------
> >  1 file changed, 10 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> > index ee652ef01534..408fe47e9db7 100644
> > --- a/drivers/misc/fastrpc.c
> > +++ b/drivers/misc/fastrpc.c
> > @@ -1830,13 +1830,13 @@ static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *
> >  	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
> >  				      &args[0]);
> >  	if (!err) {
> > -		dev_dbg(dev, "unmmap\tpt 0x%09lx OK\n", buf->raddr);
> > +		dev_dbg(dev, "unmap OK: raddr=%p\n", (void *)(unsigned long)buf->raddr);
> 
> Would it be easier if we did away with the uintptr_t, since the protocol
> seems to assume all addresses are u64s anyway?

Why is a pointer being printed at all?  That shouldn't be needed and is,
as always, a potential information leak.

thanks,

greg k-h