On Mon, Jul 31, 2023 at 9:26 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > I'm not a networking person, but I was looking at some use after free > static checker warnings. Did you refer to the gist I posted or something new? > > Apparently the rule with xmit functions is that if they return a value > > 15 then that means the skb was not freed. Otherwise it's supposed to > be freed. So like NETDEV_TX_BUSY is 0x10 so it's not freed. > > This is checked with using the dev_xmit_complete() function. So I feel > like it would make sense for LWTUNNEL_XMIT_CONTINUE to return higher > than 15. Yes I am adopting your suggestion in v5. Dealing with NETDEV_TX_BUSY would be left as another item (potentially more suited for netdev rather than bpf). Would be great to find a reproduction of memleak. > > Because that's the bug right? The original code was assuming that > everything besides LWTUNNEL_XMIT_DONE was freed. > > regards, > dan carpenter > -- Yan
