Preload shared libs that we may dlopen(). BZ 1458841

cli.py

@@ -28,6 +28,7 @@
 import math
 from optparse import OptionParser,OptionGroup,SUPPRESS_HELP
 import rpm
+import ctypes
 
 from weakref import proxy as weakref
 
@@ -805,6 +806,38 @@ def _downloadonly_userconfirm(self):
  if not inhibited:
  msg = _('Running transaction')
 
+ # Whenever we upgrade a shared library (and its dependencies) which the
+ # yum process itself may dlopen() post-transaction (e.g. in a plugin
+ # hook), we may end up in a situation where the upgraded library and
+ # the pre-transaction version of a library it depends on which is ABI
+ # incompatible are loaded in memory at the same time, leading to
+ # unpredictable behavior and possibly a crash. Let's avoid that by
+ # preloading all such dynamically loaded libraries pre-transaction so
+ # that dlopen(), if called post-transaction, uses those instead of
+ # loading the newly installed versions.
+ preload = {
+ # Loaded by libcurl, see BZ#1458841
+ 'nss-sysinit': ['libnsssysinit.so'],
+ }
+ for pkg in preload:
+ # Only preload the libs if the package is actually installed and we
+ # are changing it with the transaction
+ if not self.tsInfo.matchNaevr(name=pkg) or \
+ not self.rpmdb.searchNevra(name=pkg):
+ continue
+ for lib in preload[pkg]:
+ try:
+ ctypes.cdll.LoadLibrary(lib)
+ self.verbose_logger.log(
+ yum.logginglevels.DEBUG_4,
+ _('Preloaded shared library %s') % lib
+ )
+ except Exception as e:
+ self.verbose_logger.log(
+ yum.logginglevels.DEBUG_4,
+ _('Could not preload shared library %s: %s') % (lib, e)
+ )
+
  self.verbose_logger.log(yum.logginglevels.INFO_2, msg)
  resultobject = self.runTransaction(cb=cb)