icmp: prevent possible NULL dereferences from icmp_build_probe()

[ Upstream commit c58e88d490 ]

First problem is a double call to __in_dev_get_rcu(), because
the second one could return NULL.

if (__in_dev_get_rcu(dev) && __in_dev_get_rcu(dev)->ifa_list)

Second problem is a read from dev->ip6_ptr with no NULL check:

if (!list_empty(&rcu_dereference(dev->ip6_ptr)->addr_list))

Use the correct RCU API to fix these.

v2: add missing include <net/addrconf.h>

Fixes: d329ea5bd8 ("icmp: add response to RFC 8335 PROBE messages")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Andreas Roeseler <andreas.a.roeseler@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Eric Dumazet 2024-04-20 07:01:16 +00:00 • committed by Greg Kroah-Hartman
commit d68dc711d8