On 11/9/23 16:02, Peter Maydell wrote:
On Thu, 9 Nov 2023 at 08:06, Cédric Le Goater <clg@kaod.org> wrote:
Coverity warns that "i2c_bus_busy(i2c->busses[i]) << i" might overflow
because the expression is evaluated using 32-bit arithmetic and then
used in a context expecting a uint64_t.
Fixes: Coverity CID 1523918
Cc: Glenn Miles <milesg@linux.vnet.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
hw/ppc/pnv_i2c.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/ppc/pnv_i2c.c b/hw/ppc/pnv_i2c.c
index f75e59e70977..ab73c59f7704 100644
--- a/hw/ppc/pnv_i2c.c
+++ b/hw/ppc/pnv_i2c.c
@@ -437,7 +437,7 @@ static uint64_t pnv_i2c_xscom_read(void *opaque,
hwaddr addr,
case I2C_PORT_BUSY_REG: /* compute busy bit for each port */
val = 0;
for (i = 0; i < i2c->num_busses; i++) {
- val |= i2c_bus_busy(i2c->busses[i]) << i;
+ val |= (uint64_t) i2c_bus_busy(i2c->busses[i]) << i;
}
break;
Should the device's realize function also impose a max
limit on the num-busses property? There doesn't seem to be
anything preventing a caller from setting it to a big
number like 128, which would then be UB here.
yes. I will add an assert(i2c->num_busses < 64). The current max
is 16 for POWER10.
Style nit: casts shouldn't have a space after them before
the thing they're casting.
yep.
I prefer the cast method than the deposit call. Philippe, I hope you
don't mind ?