From f63b73814f74032c0e5d0a83300e3d864ef905e5 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Wed, 13 Nov 2019 15:44:56 +0100 Subject: Remove all loaded objects if dlopen fails, ignoring NODELETE [BZ #20839] MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This introduces a “pending NODELETE” state in the link map, which is flipped to the persistent NODELETE state late in dlopen, via activate_nodelete. During initial relocation, symbol binding records pending NODELETE state only. dlclose ignores pending NODELETE state. Taken together, this results that a partially completed dlopen is rolled back completely because new NODELETE mappings are unloaded. Tested on x86_64-linux-gnu and i386-linux-gnu. Change-Id: Ib2a3d86af6f92d75baca65431d74783ee0dbc292 --- include/link.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include') diff --git a/include/link.h b/include/link.h index be52b97370..2e771e433a 100644 --- a/include/link.h +++ b/include/link.h @@ -79,6 +79,21 @@ struct r_search_path_struct int malloced; }; +/* Type used by the l_nodelete member. */ +enum link_map_nodelete +{ + /* This link map can be deallocated. */ + link_map_nodelete_inactive = 0, /* Zero-initialized in _dl_new_object. */ + + /* This link map cannot be deallocated. */ + link_map_nodelete_active, + + /* This link map cannot be deallocated after dlopen has succeded. + dlopen turns this into link_map_nodelete_active. dlclose treats + this intermediate state as link_map_nodelete_active. */ + link_map_nodelete_pending, +}; + /* Structure describing a loaded shared object. The `l_next' and `l_prev' members form a chain of all the shared objects loaded at startup. @@ -203,6 +218,11 @@ struct link_map freed, ie. not allocated with the dummy malloc in ld.so. */ + /* Actually of type enum link_map_nodelete. Separate byte due to + a read in add_dependency in elf/dl-lookup.c outside the loader + lock. Only valid for l_type == lt_loaded. */ + unsigned char l_nodelete; + #include /* Collected information about own RPATH directories. */ -- cgit v1.2.3