The patch titled Subject: proc: fix dentry/inode overinstantiating under /proc/${pid}/net has been added to the -mm tree. Its filename is proc-fix-dentry-inode-overinstantiating-under-proc-pid-net.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/proc-fix-dentry-inode-overinstantiating-under-proc-pid-net.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/proc-fix-dentry-inode-overinstantiating-under-proc-pid-net.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Subject: proc: fix dentry/inode overinstantiating under /proc/${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. 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@xxxxxxxxx> Reported-by: hui li <juanfengpy@xxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/generic.c | 4 ++++ fs/proc/proc_net.c | 3 +++ 2 files changed, 7 insertions(+) --- a/fs/proc/generic.c~proc-fix-dentry-inode-overinstantiating-under-proc-pid-net +++ a/fs/proc/generic.c @@ -448,6 +448,10 @@ 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) _ Patches currently in -mm which might be from adobriyan@xxxxxxxxx are proc-fix-dentry-inode-overinstantiating-under-proc-pid-net.patch