From: Todd Kjos tkjos@android.com
commit 1909a671dbc3606685b1daf8b22a16f65ea7edda upstream.
syzkallar found a 32-byte memory leak in a rarely executed error case. The transaction complete work item was not freed if put_user() failed when writing the BR_TRANSACTION_COMPLETE to the user command buffer. Fixed by freeing it before put_user() is called.
Reported-by: syzbot+182ce46596c3f2e1eb24@syzkaller.appspotmail.com Signed-off-by: Todd Kjos tkjos@google.com Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/android/binder.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -4267,6 +4267,8 @@ retry: case BINDER_WORK_TRANSACTION_COMPLETE: { binder_inner_proc_unlock(proc); cmd = BR_TRANSACTION_COMPLETE; + kfree(w); + binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); if (put_user(cmd, (uint32_t __user *)ptr)) return -EFAULT; ptr += sizeof(uint32_t); @@ -4275,8 +4277,6 @@ retry: binder_debug(BINDER_DEBUG_TRANSACTION_COMPLETE, "%d:%d BR_TRANSACTION_COMPLETE\n", proc->pid, thread->pid); - kfree(w); - binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE); } break; case BINDER_WORK_NODE: { struct binder_node *node = container_of(w, struct binder_node, work);