libsepol/cil: do not dereference a NULL pointer when calloc() fails

When list_init() fails to allocate a list with calloc(), it calls
list_destroy(&l) with l = NULL. This functions starts by dereferencing
its argument ("(*list)->head"), which does not work well when it is
NULL.

This bug can be fixed by returning directly in list_init() when calloc()
fails. Doing so allows making list_init() implementation shorter by
removing label "exit" and local variable "rc".

This issue has been found using clang's static analyzer.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
1 file changed