selinux/libsepol/fuzz/binpolicy-fuzzer.c
Christian Göttsche 82438341f7 libsepol: add libfuzz based fuzzer for reading binary policies
Introduce a libfuzz[1] based fuzzer testing the parsing of a binary
policy.

Build the fuzzer in the oss-fuzz script.

[1]: https://llvm.org/docs/LibFuzzer.html

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-12-15 12:48:28 -05:00

64 lines
1.3 KiB
C

#include <sepol/debug.h>
#include <sepol/kernel_to_cil.h>
#include <sepol/kernel_to_conf.h>
#include <sepol/policydb/policydb.h>
extern int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size);
static int write_binary_policy(policydb_t *p, FILE *outfp)
{
struct policy_file pf;
policy_file_init(&pf);
pf.type = PF_USE_STDIO;
pf.fp = outfp;
return policydb_write(p, &pf);
}
int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
{
policydb_t policydb = {};
sidtab_t sidtab = {};
struct policy_file pf;
FILE *devnull = NULL;
sepol_debug(0);
policy_file_init(&pf);
pf.type = PF_USE_MEMORY;
pf.data = (char *) data;
pf.len = size;
if (policydb_init(&policydb))
goto exit;
if (policydb_read(&policydb, &pf, /*verbose=*/0))
goto exit;
if (policydb_load_isids(&policydb, &sidtab))
goto exit;
if (policydb.policy_type == POLICY_KERN)
(void) policydb_optimize(&policydb);
devnull = fopen("/dev/null", "w");
if (!devnull)
goto exit;
(void) write_binary_policy(&policydb, devnull);
(void) sepol_kernel_policydb_to_conf(devnull, &policydb);
(void) sepol_kernel_policydb_to_cil(devnull, &policydb);
exit:
if (devnull != NULL)
fclose(devnull);
policydb_destroy(&policydb);
sepol_sidtab_destroy(&sidtab);
/* Non-zero return values are reserved for future use. */
return 0;
}