Messages in this thread | | | Date | Mon, 25 Mar 2019 22:49:59 +0000 | From | Al Viro <> | Subject | Re: KASAN: use-after-free Read in path_lookupat |
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On Mon, Mar 25, 2019 at 11:04:53PM +0100, Daniel Borkmann wrote:
> +static void bpf_destroy_inode_deferred(struct rcu_head *head) > +{ > + struct inode *inode = container_of(head, struct inode, i_rcu); > + enum bpf_type type; > + > + if (S_ISLNK(inode->i_mode)) > + kfree(inode->i_link); > + if (!bpf_inode_type(inode, &type)) > + bpf_any_put(inode->i_private, type); > + free_inode_nonrcu(inode); > +}
Umm... Can bpf_any_put() can be called in that context? It's going to run in softirq; if that's OK (I'm not familiar enough with BPF guts to tell), sure, that's probably the best approach.
Note, BTW, that it's obviously -stable fodder, so any splitting of ->destroy_inode() would live on top of that fix.
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