Re: [PATCH 6.1.y] ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find()

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 90e0569dd3d32f4f4d2ca691d3fa5a8a14a13c12

WARNING: Author mismatch between patch and upstream commit:
Backport author: alvalan9@foxmail.com
Commit author: Ido Schimmel<idosch@nvidia.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Not found
6.1.y | Not found

Note: The patch differs from the upstream commit:
---
1:  90e0569dd3d32 ! 1:  2111fb1f7a15e ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find()
    @@ Metadata
      ## Commit message ##
         ipv4: ip_tunnel: Fix suspicious RCU usage warning in ip_tunnel_find()
     
    +    commit 90e0569dd3d32f4f4d2ca691d3fa5a8a14a13c12 upstream.
    +
         The per-netns IP tunnel hash table is protected by the RTNL mutex and
         ip_tunnel_find() is only called from the control path where the mutex is
         taken.
    @@ Commit message
         Reviewed-by: Eric Dumazet <edumazet@google.com>
         Link: https://patch.msgid.link/20241023123009.749764-1-idosch@nvidia.com
         Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    +    Signed-off-by: Alva Lan <alvalan9@foxmail.com>
     
      ## net/ipv4/ip_tunnel.c ##
     @@ net/ipv4/ip_tunnel.c: static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn,
    - 
    - 	ip_tunnel_flags_copy(flags, parms->i_flags);
    + 	struct ip_tunnel *t = NULL;
    + 	struct hlist_head *head = ip_bucket(itn, parms);
      
     -	hlist_for_each_entry_rcu(t, head, hash_node) {
     +	hlist_for_each_entry_rcu(t, head, hash_node, lockdep_rtnl_is_held()) {
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.1.y        |  Success    |  Success   |