On 26-Apr-19 1:31 PM, Bruce Richardson wrote:
On Fri, Apr 26, 2019 at 12:56:08PM +0100, Burakov, Anatoly wrote:
On 26-Apr-19 12:24 PM, David Hunt wrote:
coverity complains about a null-termination after a read,
so we terminate after exiting the do-while loop. The position
is conditional on whether idx is within the buffer or at the
end of the buffer.
Coverity issue: 337680
Fixes: a63504a90f ("examples/power: add JSON string handling")
CC: sta...@dpdk.org
Signed-off-by: David Hunt <david.h...@intel.com>
---
v2:
* Move null termination outside of do-while.
---
examples/vm_power_manager/channel_monitor.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/examples/vm_power_manager/channel_monitor.c
b/examples/vm_power_manager/channel_monitor.c
index 971e4f2bc..03fdcd15a 100644
--- a/examples/vm_power_manager/channel_monitor.c
+++ b/examples/vm_power_manager/channel_monitor.c
@@ -822,6 +822,8 @@ read_json_packet(struct channel_info *chan_info)
break;
} while (indent > 0);
+ json_data[idx + (idx < MAX_JSON_STRING_LEN - 1)] = '\0';
+
I don't think you need this complicated logic here. You start at idx = 0, so
even if you receive 0 bytes, you'll terminate buffer at index 0. You also
break when idx reaches (MAX_JSON_STRING_LEN - 1), so it's also safe to do
json_data[idx] after the loop. In all other cases, you still increment idx
before breaking out (e.g. when reaching indent == 0), so it's also safe to
do json_data[idx] in those cases.
+1 to that.
An alternative and simpler option might be to memset the who array to zero
before you start anyway.
That'll cost us few extra cycles on a non-performance critical path full
of syscalls, surely we can't have that! :)
/Bruce
--
Thanks,
Anatoly
