| From: Alexey Dobriyan <adobriyan@gmail.com> |
| Subject: proc: fix dentry/inode overinstantiating under /proc/${pid}/net |
| |
| When a process exits, /proc/${pid}, and /proc/${pid}/net dentries are |
| flushed. However some leaf dentries like /proc/${pid}/net/arp_cache |
| aren't. That's because respective PDEs have proc_misc_d_revalidate() hook |
| which returns 1 and leaves dentries/inodes in the LRU. |
| |
| Force revalidation/lookup on everything under /proc/${pid}/net by |
| inheriting proc_net_dentry_ops. |
| |
| [akpm@linux-foundation.org: coding-style cleanups] |
| Link: https://lkml.kernel.org/r/YjdVHgildbWO7diJ@localhost.localdomain |
| Fixes: c6c75deda813 ("proc: fix lookup in /proc/net subdirectories after setns(2)") |
| Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> |
| Reported-by: hui li <juanfengpy@gmail.com> |
| Cc: Al Viro <viro@zeniv.linux.org.uk> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| fs/proc/generic.c | 3 +++ |
| fs/proc/proc_net.c | 3 +++ |
| 2 files changed, 6 insertions(+) |
| |
| --- a/fs/proc/generic.c~proc-fix-dentry-inode-overinstantiating-under-proc-pid-net |
| +++ a/fs/proc/generic.c |
| @@ -448,6 +448,9 @@ static struct proc_dir_entry *__proc_cre |
| proc_set_user(ent, (*parent)->uid, (*parent)->gid); |
| |
| ent->proc_dops = &proc_misc_dentry_ops; |
| + /* Revalidate everything under /proc/${pid}/net */ |
| + if ((*parent)->proc_dops == &proc_net_dentry_ops) |
| + pde_force_lookup(ent); |
| |
| out: |
| return ent; |
| --- a/fs/proc/proc_net.c~proc-fix-dentry-inode-overinstantiating-under-proc-pid-net |
| +++ a/fs/proc/proc_net.c |
| @@ -376,6 +376,9 @@ static __net_init int proc_net_ns_init(s |
| |
| proc_set_user(netd, uid, gid); |
| |
| + /* Seed dentry revalidation for /proc/${pid}/net */ |
| + pde_force_lookup(netd); |
| + |
| err = -EEXIST; |
| net_statd = proc_net_mkdir(net, "stat", netd); |
| if (!net_statd) |
| _ |
