From e31f0a57ae1ab2f6e17adb8e602bc120ad722232 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 20 Sep 2023 00:12:00 -0400 Subject: [PATCH] procfs: make freeing proc_fs_info rcu-delayed makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns() is still synchronous, but that's not a problem - it does rcu-delay everything that needs to be) Reviewed-by: Christian Brauner Signed-off-by: Al Viro --- fs/proc/root.c | 2 +- include/linux/proc_fs.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/proc/root.c b/fs/proc/root.c index b55dbc70287b4..06a297a27ba3b 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -271,7 +271,7 @@ static void proc_kill_sb(struct super_block *sb) kill_anon_super(sb); put_pid_ns(fs_info->pid_ns); - kfree(fs_info); + kfree_rcu(fs_info, rcu); } static struct file_system_type proc_fs_type = { diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index de407e7c3b55f..0b2a898544409 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -65,6 +65,7 @@ struct proc_fs_info { kgid_t pid_gid; enum proc_hidepid hide_pid; enum proc_pidonly pidonly; + struct rcu_head rcu; }; static inline struct proc_fs_info *proc_sb_info(struct super_block *sb) -- 2.30.2