Unsigned integer overflow is well-defined and not undefined behavior.
But it is still useful to enable undefined behavior sanitizer checks on
unsigned arithmetic to detect possible issues on counters or variables
with similar purpose.
Annotate functions in which unsigned overflows are expected to happen.
avtab.c:76:2: runtime error: unsigned integer overflow: 6 * 3432918353 cannot be represented in type 'unsigned int'
policydb.c:795:42: runtime error: unsigned integer overflow: 8160943042179512010 * 11 cannot be represented in type 'unsigned long'
symtab.c:25:12: runtime error: left shift of 1766601759 by 4 places cannot be represented in type 'unsigned int'
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
libsepol/src/avtab.c | 6 ++++++
libsepol/src/policydb.c | 6 ++++++
libsepol/src/symtab.c | 6 ++++++
3 files changed, 18 insertions(+)
diff --git a/libsepol/src/avtab.c b/libsepol/src/avtab.c
index 257f051a..c2ccb005 100644
--- a/libsepol/src/avtab.c
+++ b/libsepol/src/avtab.c
@@ -52,6 +52,12 @@
/* Based on MurmurHash3, written by Austin Appleby and placed in the
* public domain.
*/
+#if defined(__clang__) && defined(__clang_major__) && (__clang_major__ >= 4)
+__attribute__((no_sanitize("unsigned-integer-overflow")))
+#if (__clang_major__ >= 12)
+__attribute__((no_sanitize("unsigned-shift-base")))
+#endif
+#endif
static inline int avtab_hash(struct avtab_key *keyp, uint32_t mask)
{
static const uint32_t c1 = 0xcc9e2d51;
diff --git a/libsepol/src/policydb.c b/libsepol/src/policydb.c
index fc1d0711..cbe0c432 100644
--- a/libsepol/src/policydb.c
+++ b/libsepol/src/policydb.c
@@ -789,6 +789,12 @@ static int roles_init(policydb_t * p)
goto out;
}
+#if defined(__clang__) && defined(__clang_major__) && (__clang_major__ >= 4)
+__attribute__((no_sanitize("unsigned-integer-overflow")))
+#if (__clang_major__ >= 12)
+__attribute__((no_sanitize("unsigned-shift-base")))
+#endif
+#endif
static inline unsigned long
partial_name_hash(unsigned long c, unsigned long prevhash)
{
diff --git a/libsepol/src/symtab.c b/libsepol/src/symtab.c
index 9a417ca2..738fa0a4 100644
--- a/libsepol/src/symtab.c
+++ b/libsepol/src/symtab.c
@@ -11,6 +11,12 @@
#include <sepol/policydb/hashtab.h>
#include <sepol/policydb/symtab.h>
+#if defined(__clang__) && defined(__clang_major__) && (__clang_major__ >= 4)
+__attribute__((no_sanitize("unsigned-integer-overflow")))
+#if (__clang_major__ >= 12)
+__attribute__((no_sanitize("unsigned-shift-base")))
+#endif
+#endif
static unsigned int symhash(hashtab_t h, const_hashtab_key_t key)
{
const char *p, *keyp;
--
2.32.0
