[PATCH 10/14] integrity/ima: switch to using __kernel_read

From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Ian Kent <raven@themaw.net>, David Howells <dhowells@redhat.com>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	netfilter-devel@vger.kernel.org
Subject: [PATCH 10/14] integrity/ima: switch to using __kernel_read
Date: Wed, 24 Jun 2020 18:13:31 +0200	[thread overview]
Message-ID: <20200624161335.1810359-11-hch@lst.de> (raw)
In-Reply-To: <20200624161335.1810359-1-hch@lst.de>

__kernel_read has a bunch of additional sanity checks, and this moves
the set_fs out of non-core code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 security/integrity/iint.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/security/integrity/iint.c b/security/integrity/iint.c
index e12c4900510f60..1d20003243c3fb 100644
--- a/security/integrity/iint.c
+++ b/security/integrity/iint.c
@@ -188,19 +188,7 @@ DEFINE_LSM(integrity) = {
 int integrity_kernel_read(struct file *file, loff_t offset,
 			  void *addr, unsigned long count)
 {
-	mm_segment_t old_fs;
-	char __user *buf = (char __user *)addr;
-	ssize_t ret;
-
-	if (!(file->f_mode & FMODE_READ))
-		return -EBADF;
-
-	old_fs = get_fs();
-	set_fs(KERNEL_DS);
-	ret = __vfs_read(file, buf, count, &offset);
-	set_fs(old_fs);
-
-	return ret;
+	return __kernel_read(file, addr, count, &offset);
 }
 
 /*
-- 
2.26.2

