ceph: fix race in concurrent __ceph_remove_cap invocations

A NULL pointer dereference may occur in __ceph_remove_cap with some of the
callbacks used in ceph_iterate_session_caps, namely trim_caps_cb and
remove_session_caps_cb. Those callers hold the session->s_mutex, so they
are prevented from concurrent execution, but ceph_evict_inode does not.

Since the callers of this function hold the i_ceph_lock, the fix is simply
a matter of returning immediately if caps->ci is NULL.

Cc: [email protected]
URL: https://tracker.ceph.com/issues/43272
Suggested-by: Jeff Layton <[email protected]>
Signed-off-by: Luis Henriques <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Ilya Dryomov <[email protected]>

0 files changed, 0 insertions, 0 deletions