Re: [PATCH] net: gtp: Fix Use-After-Free in gtp_dellink

On Mon, Apr 22, 2024 at 11:39 AM Hyunwoo Kim v4bel@theori.io wrote:

Since call_rcu, which is called in the hlist_for_each_entry_rcu traversal of gtp_dellink, is not part of the RCU read critical section, it is possible that the RCU grace period will pass during the traversal and the key will be free.

To prevent this, it should be changed to hlist_for_each_entry_safe.

Fixes: 94dc550a5062 ("gtp: fix an use-after-free in ipv4_pdp_find()") Signed-off-by: Hyunwoo Kim v4bel@theori.io

Reviewed-by: Eric Dumazet edumazet@google.com

Thanks !