From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: viro@ZenIV.linux.org.uk
Cc: xfs <linux-xfs@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Christoph Hellwig <hch@infradead.org>
Subject: [PATCH] vfs: check ->get_link return value
Date: Mon, 1 Oct 2018 15:45:00 -0700 [thread overview]
Message-ID: <20181001224500.GE5872@magnolia> (raw)
From: Darrick J. Wong <darrick.wong@oracle.com>
Teach callers of inode->i_op->get_link in the vfs code to check for a
NULL return value and return an error status instead of blindly
dereferencing the returned NULL pointer.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/namei.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/namei.c b/fs/namei.c
index 0cab6494978c..0744ab981fa0 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4737,6 +4737,8 @@ int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen)
if (IS_ERR(link))
return PTR_ERR(link);
}
+ if (!link)
+ return -EUCLEAN;
res = readlink_copy(buffer, buflen, link);
do_delayed_call(&done);
return res;
@@ -4763,6 +4765,8 @@ const char *vfs_get_link(struct dentry *dentry, struct delayed_call *done)
res = ERR_PTR(security_inode_readlink(dentry));
if (!res)
res = inode->i_op->get_link(dentry, inode, done);
+ if (!res)
+ return ERR_PTR(-EUCLEAN);
}
return res;
}
next reply other threads:[~2018-10-02 5:25 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-01 22:45 Darrick J. Wong [this message]
2018-10-01 23:21 ` [PATCH] vfs: check ->get_link return value Dave Chinner
2018-10-01 23:33 ` Darrick J. Wong
2018-10-01 23:53 ` Dave Chinner
2018-10-01 23:52 ` Matthew Wilcox
2018-10-02 0:23 ` Darrick J. Wong
2018-10-02 1:54 ` Al Viro
2018-10-02 1:31 ` Al Viro
2018-10-02 2:07 ` Darrick J. Wong
2018-10-02 2:47 ` Al Viro
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