All of the callers of get_ucounts are passeds a non-NULL value so stop
handling a NULL ucounts pointer in get_ucounts.
It is guaranteed that ever valid fully formed cred that is passed to
commit_cred contains a non-NULL ucounts pointer. This in turn
gurantees that current_ucounts() never returns NULL.
The call of get_ucounts in user_shm_lock is always passed
current_ucounts().
The call of get_ucounts in mqueue_get_inode is always passed
current_ucounts().
The call of get_ucounts in inc_rlmit_get_ucounts is always
passed iter, after iter has been verified to be non-NULL.
The call of get_ucounts in key_change_session_keyring is always passed
current_ucounts().
The call of get_ucounts in prepare_cred is always passed
current_ucounts().
The call of get_ucounts in prepare_kernel_cred is always
passed task->cred->ucounts or init_cred->ucounts which
being on tasks are guaranteed to have a non-NULL ucounts
field.
Link: https://lkml.kernel.org/r/87v91uqksg.fsf_-_@disp2133
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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