Christian Göttsche 97af65f696 libsepol: add checks for read sizes
Add checks for invalid read sizes from a binary policy to guard
allocations.

The common and class permission counts needs to be limited more strict
otherwise a too high count of common or class permissions can lead to
permission values with a too high value, which can lead to overflows
in shift operations.

In the fuzzer build the value will also be bounded to avoid oom reports.

    ==29857== ERROR: libFuzzer: out-of-memory (malloc(17179868160))
       To change the out-of-memory limit use -rss_limit_mb=<N>

        #0 0x52dc61 in __sanitizer_print_stack_trace (./out/binpolicy-fuzzer+0x52dc61)
        #1 0x475618 in fuzzer::PrintStackTrace() fuzzer.o
        #2 0x458855 in fuzzer::Fuzzer::HandleMalloc(unsigned long) fuzzer.o
        #3 0x45876a in fuzzer::MallocHook(void const volatile*, unsigned long) fuzzer.o
        #4 0x534557 in __sanitizer::RunMallocHooks(void const*, unsigned long) (./out/binpolicy-fuzzer+0x534557)
        #5 0x4aa7d7 in __asan::Allocator::Allocate(unsigned long, unsigned long, __sanitizer::BufferedStackTrace*, __asan::AllocType, bool) (./out/binpolicy-fuzzer+0x4aa7d7)
        #6 0x4aa143 in __asan::asan_malloc(unsigned long, __sanitizer::BufferedStackTrace*) (./out/binpolicy-fuzzer+0x4aa143)
        #7 0x5259cb in malloc (./out/binpolicy-fuzzer+0x5259cb)
        #8 0x580b5d in mallocarray ./libsepol/src/./private.h:93:9
        #9 0x57c2ed in scope_read ./libsepol/src/policydb.c:4120:7
        #10 0x576b0d in policydb_read ./libsepol/src/policydb.c:4462:9
        #11 0x55a214 in LLVMFuzzerTestOneInput ./libsepol/fuzz/binpolicy-fuzzer.c:26:6
        #12 0x45aed3 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) fuzzer.o
        #13 0x446a12 in fuzzer::RunOneTest(fuzzer::Fuzzer*, char const*, unsigned long) fuzzer.o
        #14 0x44c93b in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) fuzzer.o
        #15 0x475dd2 in main (./out/binpolicy-fuzzer+0x475dd2)
        #16 0x7ffad6e107ec in __libc_start_main csu/../csu/libc-start.c:332:16
        #17 0x423689 in _start (./out/binpolicy-fuzzer+0x423689)

    ==19462== ERROR: libFuzzer: out-of-memory (malloc(18253611008))
       To change the out-of-memory limit use -rss_limit_mb=<N>

        #0 0x52dc61 in __sanitizer_print_stack_trace (./out/binpolicy-fuzzer+0x52dc61)
        #1 0x475618 in fuzzer::PrintStackTrace() fuzzer.o
        #2 0x458855 in fuzzer::Fuzzer::HandleMalloc(unsigned long) fuzzer.o
        #3 0x45876a in fuzzer::MallocHook(void const volatile*, unsigned long) fuzzer.o
        #4 0x534557 in __sanitizer::RunMallocHooks(void const*, unsigned long) (./out/binpolicy-fuzzer+0x534557)
        #5 0x4aa7d7 in __asan::Allocator::Allocate(unsigned long, unsigned long, __sanitizer::BufferedStackTrace*, __asan::AllocType, bool) (./out/binpolicy-fuzzer+0x4aa7d7)
        #6 0x4aa999 in __asan::asan_calloc(unsigned long, unsigned long, __sanitizer::BufferedStackTrace*) (./out/binpolicy-fuzzer+0x4aa999)
        #7 0x525b63 in __interceptor_calloc (./out/binpolicy-fuzzer+0x525b63)
        #8 0x570938 in policydb_index_others ./libsepol/src/policydb.c:1245:6
        #9 0x5771f3 in policydb_read ./src/policydb.c:4481:6
        #10 0x55a214 in LLVMFuzzerTestOneInput ./libsepol/fuzz/binpolicy-fuzzer.c:26:6
        #11 0x45aed3 in fuzzer::Fuzzer::ExecuteCallback(unsigned char const*, unsigned long) fuzzer.o
        #12 0x446a12 in fuzzer::RunOneTest(fuzzer::Fuzzer*, char const*, unsigned long) fuzzer.o
        #13 0x44c93b in fuzzer::FuzzerDriver(int*, char***, int (*)(unsigned char const*, unsigned long)) fuzzer.o
        #14 0x475dd2 in main (./out/binpolicy-fuzzer+0x475dd2)
        #15 0x7f4d933157ec in __libc_start_main csu/../csu/libc-start.c:332:16
        #16 0x423689 in _start (./out/binpolicy-fuzzer+0x423689)

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
2021-12-15 12:48:45 -05:00
..
2021-12-15 12:48:45 -05:00
2014-08-26 08:03:31 -04:00
2014-08-26 08:03:31 -04:00
2021-10-21 16:31:23 +02:00