This is a note to let you know that I've just added the patch titled
ion: Fix use after free during ION_IOC_ALLOC
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ion-fix-use-after-free-during-ion_ioc_alloc.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Jan 27 04:37:00 PM CET 2022
From: Lee Jones <lee.jones@xxxxxxxxxx>
Date: Tue, 25 Jan 2022 14:18:06 +0000
Subject: ion: Fix use after free during ION_IOC_ALLOC
To: lee.jones@xxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx, Daniel Rosenberg <drosen@xxxxxxxxxx>, Dennis Cagle <d-cagle@xxxxxxxxxxxxxx>, Patrick Daly <pdaly@xxxxxxxxxxxxxx>
Message-ID: <20220125141808.1172511-1-lee.jones@xxxxxxxxxx>
From: Daniel Rosenberg <drosen@xxxxxxxxxx>
If a user happens to call ION_IOC_FREE during an ION_IOC_ALLOC
on the just allocated id, and the copy_to_user fails, the cleanup
code will attempt to free an already freed handle.
This adds a wrapper for ion_alloc that adds an ion_handle_get to
avoid this.
Signed-off-by: Daniel Rosenberg <drosen@xxxxxxxxxx>
Signed-off-by: Dennis Cagle <d-cagle@xxxxxxxxxxxxxx>
Signed-off-by: Patrick Daly <pdaly@xxxxxxxxxxxxxx>
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/android/ion/ion-ioctl.c | 14 +++++++++-----
drivers/staging/android/ion/ion.c | 15 ++++++++++++---
drivers/staging/android/ion/ion.h | 4 ++++
3 files changed, 25 insertions(+), 8 deletions(-)
--- a/drivers/staging/android/ion/ion-ioctl.c
+++ b/drivers/staging/android/ion/ion-ioctl.c
@@ -96,10 +96,10 @@ long ion_ioctl(struct file *filp, unsign
{
struct ion_handle *handle;
- handle = ion_alloc(client, data.allocation.len,
- data.allocation.align,
- data.allocation.heap_id_mask,
- data.allocation.flags);
+ handle = __ion_alloc(client, data.allocation.len,
+ data.allocation.align,
+ data.allocation.heap_id_mask,
+ data.allocation.flags, true);
if (IS_ERR(handle))
return PTR_ERR(handle);
@@ -174,10 +174,14 @@ long ion_ioctl(struct file *filp, unsign
if (dir & _IOC_READ) {
if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd))) {
- if (cleanup_handle)
+ if (cleanup_handle) {
ion_free(client, cleanup_handle);
+ ion_handle_put(cleanup_handle);
+ }
return -EFAULT;
}
}
+ if (cleanup_handle)
+ ion_handle_put(cleanup_handle);
return ret;
}
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -401,9 +401,9 @@ static int ion_handle_add(struct ion_cli
return 0;
}
-struct ion_handle *ion_alloc(struct ion_client *client, size_t len,
- size_t align, unsigned int heap_id_mask,
- unsigned int flags)
+struct ion_handle *__ion_alloc(struct ion_client *client, size_t len,
+ size_t align, unsigned int heap_id_mask,
+ unsigned int flags, bool grab_handle)
{
struct ion_handle *handle;
struct ion_device *dev = client->dev;
@@ -453,6 +453,8 @@ struct ion_handle *ion_alloc(struct ion_
return handle;
mutex_lock(&client->lock);
+ if (grab_handle)
+ ion_handle_get(handle);
ret = ion_handle_add(client, handle);
mutex_unlock(&client->lock);
if (ret) {
@@ -462,6 +464,13 @@ struct ion_handle *ion_alloc(struct ion_
return handle;
}
+
+struct ion_handle *ion_alloc(struct ion_client *client, size_t len,
+ size_t align, unsigned int heap_id_mask,
+ unsigned int flags)
+{
+ return __ion_alloc(client, len, align, heap_id_mask, flags, false);
+}
EXPORT_SYMBOL(ion_alloc);
void ion_free_nolock(struct ion_client *client,
--- a/drivers/staging/android/ion/ion.h
+++ b/drivers/staging/android/ion/ion.h
@@ -109,6 +109,10 @@ struct ion_handle *ion_alloc(struct ion_
size_t align, unsigned int heap_id_mask,
unsigned int flags);
+struct ion_handle *__ion_alloc(struct ion_client *client, size_t len,
+ size_t align, unsigned int heap_id_mask,
+ unsigned int flags, bool grab_handle);
+
/**
* ion_free - free a handle
* @client: the client
Patches currently in stable-queue which might be from lee.jones@xxxxxxxxxx are
queue-4.9/ion-protect-kref-from-userspace-manipulation.patch
queue-4.9/ion-do-not-put-ion-handle-until-after-its-final-use.patch
queue-4.9/ion-fix-use-after-free-during-ion_ioc_alloc.patch
