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.
Fixes: c6c75deda813 ("proc: fix lookup in /proc/net subdirectories after setns(2)")
Reported-by: hui li <juanfengpy@xxxxxxxxx>
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
---
fs/proc/generic.c | 4 ++++
fs/proc/proc_net.c | 3 +++
2 files changed, 7 insertions(+)
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -448,6 +448,10 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
proc_set_user(ent, (*parent)->uid, (*parent)->gid);
ent->proc_dops = &proc_misc_dentry_ops;
+ /* Revalidate everything under /proc/${pid}/net */
+ if ((*parent)->proc_dops == &proc_net_dentry_ops) {
+ pde_force_lookup(ent);
+ }
out:
return ent;
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -376,6 +376,9 @@ static __net_init int proc_net_ns_init(struct net *net)
proc_set_user(netd, uid, gid);
+ /* Seed dentry revalidation for /proc/${pid}/net */
+ pde_force_lookup(netd);
+
err = -EEXIST;
net_statd = proc_net_mkdir(net, "stat", netd);
if (!net_statd)
