[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20190523181739.841945536@linuxfoundation.org>
Date: Thu, 23 May 2019 21:06:32 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Al Viro <viro@...iv.linux.org.uk>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 093/114] apparmorfs: fix use-after-free on symlink traversal
[ Upstream commit f51dcd0f621caac5380ce90fbbeafc32ce4517ae ]
symlink body shouldn't be freed without an RCU delay. Switch apparmorfs
to ->destroy_inode() and use of call_rcu(); free both the inode and symlink
body in the callback.
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
security/apparmor/apparmorfs.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index e09fe4d7307cd..40e3a098f6fb5 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -123,17 +123,22 @@ static int aafs_show_path(struct seq_file *seq, struct dentry *dentry)
return 0;
}
-static void aafs_evict_inode(struct inode *inode)
+static void aafs_i_callback(struct rcu_head *head)
{
- truncate_inode_pages_final(&inode->i_data);
- clear_inode(inode);
+ struct inode *inode = container_of(head, struct inode, i_rcu);
if (S_ISLNK(inode->i_mode))
kfree(inode->i_link);
+ free_inode_nonrcu(inode);
+}
+
+static void aafs_destroy_inode(struct inode *inode)
+{
+ call_rcu(&inode->i_rcu, aafs_i_callback);
}
static const struct super_operations aafs_super_ops = {
.statfs = simple_statfs,
- .evict_inode = aafs_evict_inode,
+ .destroy_inode = aafs_destroy_inode,
.show_path = aafs_show_path,
};
--
2.20.1
Powered by blists - more mailing lists