On 2021-08-13 15:54, Ben Greear wrote: > On 8/13/21 3:15 AM, Felix Fietkau wrote: >> >> On 2021-07-31 04:17, Ryder Lee wrote: >>> From: Ben Greear <greearb@xxxxxxxxxxxxxxx> >>> >>> Without this change, garbage is seen in the hwmon name >>> and sensors output for mt7915 is garbled. >> Where does the use-after-free bug come from? It's not obvious to me why >> using KBUILD_MODNAME instead of wiphy_name() fixes it. >> I still think the phy name should probably be part of the prefix. > > We rename phy devices as part of our normal operation, I think maybe > that helps trigger the bug. > > It appears that the hwmon logic does not make a copy of the incoming string, > but instead just copies a char* and expects it to never go away. But, > I did not actually verify that. That makes sense. It seems that thermal copies the string internally, but hwmon does not. How about using devm_kstrdup on the wiphy name instead of using KBUILD_MODNAME? If you really don't want to use the initial phy name, there's also the option of using dev_name(dev->mt76.dev) - Felix
