libsepol: make role_list_destroy() do nothing when role_list is NULL
When a function called by sepol_module_policydb_to_cil() fails before
role_list_create() has been called, role_list is still NULL but is
dereferenced in role_list_destroy(). Here is a gdb session on hll/pp:
Unknown value for handle-unknown: 6
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7a68a37 in role_list_destroy () at module_to_cil.c:215
215 struct list_node *curr = role_list->head;
(gdb) bt
#0 0x00007ffff7a68a37 in role_list_destroy () at
module_to_cil.c:215
#1 sepol_module_policydb_to_cil (fp=fp@entry=0x7ffff79925e0
<_IO_2_1_stdout_>, pdb=<optimized out>, linked=linked@entry=0) at
module_to_cil.c:4060
#2 0x00007ffff7a6ac75 in sepol_module_package_to_cil
(fp=fp@entry=0x7ffff79925e0 <_IO_2_1_stdout_>, mod_pkg=0x604280) at
module_to_cil.c:4080
#3 0x0000000000401a58 in main (argc=<optimized out>,
argv=<optimized out>) at pp.c:150
This issue has been found while fuzzing hll/pp with the American Fuzzy
Lop.
Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
1 file changed