From: Alexey Dobriyan adobriyan@gmail.com
stable inclusion from stable-v5.10.121 commit f061ddfed9a70155c17d8e80737b9224b3b96ffd category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 7055197705709c59b8ab77e6a5c7d46d61edd96e ]
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 Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- fs/proc/generic.c | 3 +++ fs/proc/proc_net.c | 3 +++ 2 files changed, 6 insertions(+)
diff --git a/fs/proc/generic.c b/fs/proc/generic.c index 09e4d8a499a3..5898761698c2 100644 --- a/fs/proc/generic.c +++ b/fs/proc/generic.c @@ -453,6 +453,9 @@ 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/${pid}/net */ + if ((*parent)->proc_dops == &proc_net_dentry_ops) + pde_force_lookup(ent);
out: return ent; diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c index 1aa9236bf1af..707477e27f83 100644 --- a/fs/proc/proc_net.c +++ b/fs/proc/proc_net.c @@ -362,6 +362,9 @@ static __net_init int proc_net_ns_init(struct net *net)
proc_set_user(netd, uid, gid);
+ /* Seed dentry revalidation for /proc/${pid}/net */ + pde_force_lookup(netd); + err = -EEXIST; net_statd = proc_net_mkdir(net, "stat", netd); if (!net_statd)