Re: [PATCH v6.1.y 4/4] ipv4: start using dst_dev_rcu()

On Fri, Aug 21, 2026 at 03:33:38PM +0200, Miguel Gazquez (Schneider Electric) wrote:

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 6ad8de3cefdb6ffa6708b21c567df0dbf82c43a8 ]

Change icmpv4_xrlim_allow(), ip_defrag() to prevent possible UAF.

Change ipmr_prepare_xmit(), ipmr_queue_fwd_xmit(), ip_mr_output(),
ipv4_neigh_lookup() to use lockdep enabled dst_dev_rcu().

Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250828195823.3958522-9-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ minor modifications to fix conflict, added rcu_read_lock and unlock
to ip_defrag function ]
Signed-off-by: Miguel Gazquez (Schneider Electric) <redacted>

We need a working 6.6.y version first, before we can take this one.

thanks,

greg k-h