ceph: correctly handle releasing an embedded cap flush
commit b2f9fa1f upstream. The ceph_cap_flush structures are usually dynamically allocated, but the ceph_cap_snap has an embedded one. When force umounting, the client will try to remove all the session caps. During this, it will free them, but that should not be done with the ones embedded in a capsnap. Fix this by adding a new boolean that indicates that the cap flush is embedded in a capsnap, and skip freeing it if that's set. At the same time, switch to using list_del_init() when detaching the i_list and g_list heads. It's possible for a forced umount to remove these objects but then handle_cap_flushsnap_ack() races in and does the list_del_init() again, corrupting memory. Cc: stable@vger.kernel.org URL: https://tracker.ceph.com/issues/52283 Signed-off-by:Xiubo Li <xiubli@redhat.com> Reviewed-by:
Jeff Layton <jlayton@kernel.org> Signed-off-by:
Ilya Dryomov <idryomov@gmail.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
7008b998
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