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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Chris Mason <chris.mason@fusionio.com>,
	Alexander Block <ablock84@googlemail.com>
Cc: linux-btrfs@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [patch] Btrfs: fix access_ok() check in btrfs_ioctl_send()
Date: Thu, 10 Jan 2013 08:57:25 +0000	[thread overview]
Message-ID: <20130110085725.GA23063@elgon.mountain> (raw)

The closing parenthesis is in the wrong place.  We want to check
"sizeof(*arg->clone_sources) * arg->clone_sources_count" instead of
"sizeof(*arg->clone_sources * arg->clone_sources_count)".

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
This is also vulnerable to integer overflows.  It's only done under
root, but these days we are trying to restrict what root can do without
configuring Secure Boot in UEFI.

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 5445454..4be3832 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -4553,8 +4553,8 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
 	}
 
 	if (!access_ok(VERIFY_READ, arg->clone_sources,
-			sizeof(*arg->clone_sources *
-			arg->clone_sources_count))) {
+			sizeof(*arg->clone_sources) *
+			arg->clone_sources_count)) {
 		ret = -EFAULT;
 		goto out;
 	}

             reply	other threads:[~2013-01-10  8:57 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-10  8:57 Dan Carpenter [this message]
2013-01-10  9:21 ` [patch] Btrfs: fix access_ok() check in btrfs_ioctl_send() Jeff Liu
2013-10-21 12:30 ` David Sterba
2013-11-18 10:57   ` David Sterba

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