On Thu, 10 Jun 2021 23:39:41 +0800 Changbin Du wrote: > There is a panic in socket ioctl cmd SIOCGSKNS when NET_NS is not enabled. > The reason is that nsfs tries to access ns->ops but the proc_ns_operations > is not implemented in this case. > > [7.670023] Unable to handle kernel NULL pointer dereference at virtual address 00000010 > [7.670268] pgd = 32b54000 > [7.670544] [00000010] *pgd=00000000 > [7.671861] Internal error: Oops: 5 [#1] SMP ARM > [7.672315] Modules linked in: > [7.672918] CPU: 0 PID: 1 Comm: systemd Not tainted 5.13.0-rc3-00375-g6799d4f2da49 #16 > [7.673309] Hardware name: Generic DT based system > [7.673642] PC is at nsfs_evict+0x24/0x30 > [7.674486] LR is at clear_inode+0x20/0x9c > > The same to tun SIOCGSKNS command. > > To fix this problem, we make get_net_ns() return -EINVAL when NET_NS is > disabled. Meanwhile move it to right place net/core/net_namespace.c. I'm assuming you went from EOPNOTSUPP to EINVAL to follow what the existing helpers in the header do? Acked-by: Jakub Kicinski <kuba@xxxxxxxxxx> Thanks!
