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Subject[PATCH 4.14 10/75] ANDROID: binder: fix transaction leak.
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Martijn Coenen <maco@android.com>

commit fb2c445277e7b0b4ffe10de8114bad4eccaca948 upstream.

If a call to put_user() fails, we failed to
properly free a transaction and send a failed
reply (if necessary).

Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/android/binder.c | 40 +++++++++++++++++++++++++++++++---------
1 file changed, 31 insertions(+), 9 deletions(-)

--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -1948,6 +1948,26 @@ static void binder_send_failed_reply(str
}

/**
+ * binder_cleanup_transaction() - cleans up undelivered transaction
+ * @t: transaction that needs to be cleaned up
+ * @reason: reason the transaction wasn't delivered
+ * @error_code: error to return to caller (if synchronous call)
+ */
+static void binder_cleanup_transaction(struct binder_transaction *t,
+ const char *reason,
+ uint32_t error_code)
+{
+ if (t->buffer->target_node && !(t->flags & TF_ONE_WAY)) {
+ binder_send_failed_reply(t, error_code);
+ } else {
+ binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
+ "undelivered transaction %d, %s\n",
+ t->debug_id, reason);
+ binder_free_transaction(t);
+ }
+}
+
+/**
* binder_validate_object() - checks for a valid metadata object in a buffer.
* @buffer: binder_buffer that we're parsing.
* @offset: offset in the buffer at which to validate an object.
@@ -4015,12 +4035,20 @@ retry:
if (put_user(cmd, (uint32_t __user *)ptr)) {
if (t_from)
binder_thread_dec_tmpref(t_from);
+
+ binder_cleanup_transaction(t, "put_user failed",
+ BR_FAILED_REPLY);
+
return -EFAULT;
}
ptr += sizeof(uint32_t);
if (copy_to_user(ptr, &tr, sizeof(tr))) {
if (t_from)
binder_thread_dec_tmpref(t_from);
+
+ binder_cleanup_transaction(t, "copy_to_user failed",
+ BR_FAILED_REPLY);
+
return -EFAULT;
}
ptr += sizeof(tr);
@@ -4090,15 +4118,9 @@ static void binder_release_work(struct b
struct binder_transaction *t;

t = container_of(w, struct binder_transaction, work);
- if (t->buffer->target_node &&
- !(t->flags & TF_ONE_WAY)) {
- binder_send_failed_reply(t, BR_DEAD_REPLY);
- } else {
- binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,
- "undelivered transaction %d\n",
- t->debug_id);
- binder_free_transaction(t);
- }
+
+ binder_cleanup_transaction(t, "process died.",
+ BR_DEAD_REPLY);
} break;
case BINDER_WORK_RETURN_ERROR: {
struct binder_error *e = container_of(

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