From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> [ Upstream commit e3af3d3c5b26c33a7950e34e137584f6056c4319 ] dev->ip_ptr could be NULL if we set an invalid MTU. Even then, if we issue ioctl(SIOCSIFADDR) for a new IPv4 address, devinet_ioctl() allocates struct in_ifaddr and fails later in inet_set_ifa() because in_dev is NULL. Let's move the check earlier. Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> Link: https://patch.msgid.link/20240809235406.50187-2-kuniyu@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/ipv4/devinet.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index d09f557eaa779..73effd2d2994a 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -574,10 +574,6 @@ static int inet_set_ifa(struct net_device *dev, struct in_ifaddr *ifa) ASSERT_RTNL(); - if (!in_dev) { - inet_free_ifa(ifa); - return -ENOBUFS; - } ipv4_devconf_setall(in_dev); neigh_parms_data_state_setall(in_dev->arp_parms); if (ifa->ifa_dev != in_dev) { @@ -1184,6 +1180,8 @@ int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr) if (!ifa) { ret = -ENOBUFS; + if (!in_dev) + break; ifa = inet_alloc_ifa(); if (!ifa) break; -- 2.43.0