Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu. Pushed to trunk as r14-6349-g0bef72539e585d.
gcc/analyzer/ChangeLog: * sm-taint.cc (taint_state_machine::alt_get_inherited_state): Fix handling of TRUNC_MOD_EXPR. gcc/testsuite/ChangeLog: * c-c++-common/analyzer/taint-modulus-1.c: New test. --- gcc/analyzer/sm-taint.cc | 9 ++++++++- gcc/testsuite/c-c++-common/analyzer/taint-modulus-1.c | 8 ++++++++ 2 files changed, 16 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/c-c++-common/analyzer/taint-modulus-1.c diff --git a/gcc/analyzer/sm-taint.cc b/gcc/analyzer/sm-taint.cc index 6b5d51c62af..597e8e55609 100644 --- a/gcc/analyzer/sm-taint.cc +++ b/gcc/analyzer/sm-taint.cc @@ -891,7 +891,6 @@ taint_state_machine::alt_get_inherited_state (const sm_state_map &map, case MULT_EXPR: case POINTER_PLUS_EXPR: case TRUNC_DIV_EXPR: - case TRUNC_MOD_EXPR: { state_t arg0_state = map.get_state (arg0, ext_state); state_t arg1_state = map.get_state (arg1, ext_state); @@ -899,6 +898,14 @@ taint_state_machine::alt_get_inherited_state (const sm_state_map &map, } break; + case TRUNC_MOD_EXPR: + { + /* The left-hand side of X % Y can be sanitized by + the operation. */ + return map.get_state (arg1, ext_state); + } + break; + case BIT_AND_EXPR: case RSHIFT_EXPR: return NULL; diff --git a/gcc/testsuite/c-c++-common/analyzer/taint-modulus-1.c b/gcc/testsuite/c-c++-common/analyzer/taint-modulus-1.c new file mode 100644 index 00000000000..ed286fa341c --- /dev/null +++ b/gcc/testsuite/c-c++-common/analyzer/taint-modulus-1.c @@ -0,0 +1,8 @@ +#define SIZE 16 +char buf[SIZE]; + +__attribute__ ((tainted_args)) +char test_sanitized_by_modulus (int val) +{ + return buf[val % SIZE]; /* { dg-bogus "use of attacker-controlled value" } */ +} -- 2.26.3