binder_alloc: add missing mmap_lock calls when using the VMA
authorLiam Howlett <liam.howlett@oracle.com>
Wed, 10 Aug 2022 16:02:25 +0000 (16:02 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 31 Aug 2022 15:16:50 +0000 (17:16 +0200)
commit577d9c05cc48c5242bcf719c06a5baf3105473ad
tree78ec100665077c3f1a3fa3de27b19514c3e075c9
parent1ed630bc530ae107d32c41156b836ee95651e33c
binder_alloc: add missing mmap_lock calls when using the VMA

commit 44e602b4e52f70f04620bbbf4fe46ecb40170bde upstream.

Take the mmap_read_lock() when using the VMA in binder_alloc_print_pages()
and when checking for a VMA in binder_alloc_new_buf_locked().

It is worth noting binder_alloc_new_buf_locked() drops the VMA read lock
after it verifies a VMA exists, but may be taken again deeper in the call
stack, if necessary.

Link: https://lkml.kernel.org/r/20220810160209.1630707-1-Liam.Howlett@oracle.com
Fixes: a43cfc87caaf (android: binder: stop saving a pointer to the VMA)
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Ondrej Mosnacek <omosnace@redhat.com>
Reported-by: <syzbot+a7b60a176ec13cafb793@syzkaller.appspotmail.com>
Acked-by: Carlos Llamas <cmllamas@google.com>
Tested-by: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Christian Brauner (Microsoft) <brauner@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Martijn Coenen <maco@android.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Todd Kjos <tkjos@android.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Arve Hjønnevåg" <arve@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/android/binder_alloc.c