This is a note to let you know that I've just added the patch titled ipv4: Check !in_dev earlier for ioctl(SIOCSIFADDR). to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv4-check-in_dev-earlier-for-ioctl-siocsifaddr.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit bf4618f00ffd66997ac923bb976db3b9e639478b Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> Date: Fri Aug 9 16:54:02 2024 -0700 ipv4: Check !in_dev earlier for ioctl(SIOCSIFADDR). [ 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> diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 425dfa8e4fd0a..da0f49d77c011 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -566,10 +566,6 @@ 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) { @@ -1149,6 +1145,8 @@ 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;