binder: prevent UAF read in print_binder_transaction_log_entry()
When a binder transaction is initiated on a binder device coming from a
binderfs instance, a pointer to the name of the binder device is stashed
in the binder_transaction_log_entry's context_name member. Later on it
is used to print the name in print_binder_transaction_log_entry(). By
the time print_binder_transaction_log_entry() accesses context_name
binderfs_evict_inode() might have already freed the associated memory
thereby causing a UAF. Do the simple thing and prevent this by copying
the name of the binder device instead of stashing a pointer to it.
Reported-by: Jann Horn <jannh@google.com>
Fixes: 03e2e07e3814 ("binder: Make transaction_log available in binderfs")
Link: https://lore.kernel.org/r/CAG48ez14Q0-F8LqsvcNbyR2o6gPW8SHXsm4u5jmD9MpsteM2Tw@mail.gmail.com
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Todd Kjos <tkjos@android.com>
Cc: Hridya Valsaraju <hridya@google.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2 files changed
