On 1/28/21 11:44 AM, Peter Krempa wrote:
On Thu, Jan 28, 2021 at 11:24:36 +0100, Tim Wiederhake wrote:
If "udevGetDeviceSysfsAttr()" returns NULL, "udevGetIntSysfsAttr" would return "0", indicating success, without writing to "value".
This was found by clang-tidy's "clang-analyzer-core.UndefinedBinaryOperatorResult" check in function "udevProcessCCW", flagging a read on the potentially uninitialized variable "online".
Signed-off-by: Tim Wiederhake <twiederh@redhat.com> --- src/node_device/node_device_udev.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c index 55a2731681..d5a12bab0e 100644 --- a/src/node_device/node_device_udev.c +++ b/src/node_device/node_device_udev.c @@ -254,7 +254,10 @@ udevGetIntSysfsAttr(struct udev_device *udev_device,
str = udevGetDeviceSysfsAttr(udev_device, attr_name);
- if (str && virStrToLong_i(str, NULL, base, value) < 0) { + if (!str) + return -1;
In this case an error wouldn't be reported any more.
I think it's quite the opposite actually. Previously, if str == NULL then a zero was returned (without any error) from this function. Now you get -1. I think we want to keep return 0 in case of !str. Callers use the following pattern: var = -1; /* default */ udevGetIntSysfsAttr(device, "attribute", &var, 10); If "attribute" exists, @var is updated; if it doesn't it's left untouched with the default value (-1 in this case). Michal