arp: switch to dev_getbyhwaddr() in arp_req_set_public()

[ Upstream commit 4eae0ee0f1e6256d0b0b9dd6e72f1d9cf8f72e08 ]

The arp_req_set_public() function is called with the rtnl lock held,
which provides enough synchronization protection. This makes the RCU
variant of dev_getbyhwaddr() unnecessary. Switch to using the simpler
dev_getbyhwaddr() function since we already have the required rtnl
locking.

This change helps maintain consistency in the networking code by using
the appropriate helper function for the existing locking context.
Since we're not holding the RCU read lock in arp_req_set_public()
existing code could trigger false positive locking warnings.

Fixes: 941666c2e3e0 ("net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()")
Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250218-arm_fix_selftest-v5-2-d3d6892db9e1@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 59ffaa89d7b05fdc7d652a491ddf2bd7407b1f79..8fb48f42581ce15ba71a1d6cb7515797a588cf5b 100644 (file)
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -1077,7 +1077,7 @@ static int arp_req_set_public(struct net *net, struct arpreq *r,
        __be32 mask = ((struct sockaddr_in *)&r->arp_netmask)->sin_addr.s_addr;
 
        if (!dev && (r->arp_flags & ATF_COM)) {
-               dev = dev_getbyhwaddr_rcu(net, r->arp_ha.sa_family,
+               dev = dev_getbyhwaddr(net, r->arp_ha.sa_family,
                                      r->arp_ha.sa_data);
                if (!dev)
                        return -ENODEV;