Re: [PATCH 0/3] Avoid calling WARN_ON() on allocation failure in cfg802154_switch_netns()

[Kuniyuki Iwashima]

From: Ivan Abramov <i.abramov@xxxxxxxxxxxxxxxxx>
Date: Fri, 28 Mar 2025 04:04:24 +0300
> This series was inspired by Syzkaller report on warning in
> cfg802154_switch_netns().
> 
> WARNING: CPU: 0 PID: 5837 at net/ieee802154/core.c:258 cfg802154_switch_netns+0x3c7/0x3d0 net/ieee802154/core.c:258
> Modules linked in:
> CPU: 0 UID: 0 PID: 5837 Comm: syz-executor125 Not tainted 6.13.0-rc6-syzkaller-00918-g7b24f164cf00 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
> RIP: 0010:cfg802154_switch_netns+0x3c7/0x3d0 net/ieee802154/core.c:258
> Call Trace:
>  <TASK>
>  nl802154_wpan_phy_netns+0x13d/0x210 net/ieee802154/nl802154.c:1292
>  genl_family_rcv_msg_doit net/netlink/genetlink.c:1115 [inline]
>  genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
>  genl_rcv_msg+0xb14/0xec0 net/netlink/genetlink.c:1210
>  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543
>  genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
>  netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
>  netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348
>  netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1892
>  sock_sendmsg_nosec net/socket.c:711 [inline]
>  __sock_sendmsg+0x221/0x270 net/socket.c:726
>  ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2594
>  ___sys_sendmsg net/socket.c:2648 [inline]
>  __sys_sendmsg+0x269/0x350 net/socket.c:2680
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> This warning is caused by Syzkaller's fault injection, which causes
> kstrdup() in device_rename() to fail, so device_rename() returns -ENOMEM.
> 
> Since practically such failure is not possible, avoid it, additionally
> fixing similar pointless allocation-related warnings.
> 
> Ivan Abramov (3):
>   ieee802154: Restore initial state on failed device_rename() in
>     cfg802154_switch_netns()
>   ieee802154: Avoid calling WARN_ON() on -ENOMEM in
>     cfg802154_switch_netns()
>   ieee802154: Remove WARN_ON() in cfg802154_pernet_exit()

While at it, apply the same change to cfg80211_switch_netns() and
cfg80211_pernet_exit().

Thanks!


> 
>  net/ieee802154/core.c | 51 ++++++++++++++++++++++++-------------------
>  1 file changed, 29 insertions(+), 22 deletions(-)
> 
> --