binder: fix potential UAF of target_{proc,thread}
authorCarlos Llamas <cmllamas@google.com>
Tue, 17 May 2022 18:58:17 +0000 (18:58 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 19 May 2022 16:41:26 +0000 (18:41 +0200)
commitdafa5e9ab8b5b31d64c0ded188d95f8bb6be9746
treee858cd584328605834333c3d898e6d8971119720
parentda4864962d768b33e3bc31cd233270af6226686d
binder: fix potential UAF of target_{proc,thread}

Commit 9474be34a727 ("binder: add failed transaction logging info")
dereferences target_{proc,thread} after they have been potentially
freed by binder_proc_dec_tmpref() and binder_thread_dec_tmpref().

This patch delays the release of the two references after their last
usage. Fixes the following two errors reported by smatch:

  drivers/android/binder.c:3562 binder_transaction() error: dereferencing freed memory 'target_proc'
  drivers/android/binder.c:3563 binder_transaction() error: dereferencing freed memory 'target_thread'

Fixes: 9474be34a727 ("binder: add failed transaction logging info")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20220517185817.598872-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/android/binder.c