On Tue, Jul 31, 2018 at 05:00:38PM -0700, Kees Cook wrote: > + /* Overflow: high bit falls off. */ > + /* 10010110 */ > + err |= TEST_ONE_SHIFT(150, 1, u8, 0, true); > + /* 1000100010010110 */ > + err |= TEST_ONE_SHIFT(34966, 1, u16, 0, true); > + /* 10000100000010001000100010010110 */ > + err |= TEST_ONE_SHIFT(2215151766U, 1, u32, 0, true); > + err |= TEST_ONE_SHIFT(2215151766U, 1, unsigned int, 0, true); > + /* 1000001000010000010000000100000010000100000010001000100010010110 */ > + err |= TEST_ONE_SHIFT(9372061470395238550ULL, 1, u64, 0, true);
This same idea should be repeated with signed outputs and check both overflow past the end (<<2) and overflow into the signed bit (<<1) /* Overflow, high bit falls into the sign bit or off the end */ /* 01001011 */ err |= TEST_ONE_SHIFT(75, 1, s8, 0, true); err |= TEST_ONE_SHIFT(75, 2, s8, 0, true); And also general type mismatch overflow: err |= TEST_ONE_SHIFT(0x100, 0, u8, 0, true); err |= TEST_ONE_SHIFT(0xFF, 0, s8, 0, true); Thanks, Jason