autofs: fix use-after-free in lockless ->d_manage()
autofs_d_release() can overlap with lockless ->d_manage(),
ending up with autofs_dentry_ino() freed under the latter.
Make freeing autofs_info instances RCU-delayed...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h
index 70c132a..e109131 100644
--- a/fs/autofs/autofs_i.h
+++ b/fs/autofs/autofs_i.h
@@ -71,6 +71,7 @@ struct autofs_info {
kuid_t uid;
kgid_t gid;
+ struct rcu_head rcu;
};
#define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */
diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
index 80597b8..fb0225f 100644
--- a/fs/autofs/inode.c
+++ b/fs/autofs/inode.c
@@ -36,7 +36,7 @@ void autofs_clean_ino(struct autofs_info *ino)
void autofs_free_ino(struct autofs_info *ino)
{
- kfree(ino);
+ kfree_rcu(ino, rcu);
}
void autofs_kill_sb(struct super_block *sb)
