public inbox for linux-xfs@vger.kernel.org
 help / color / mirror / Atom feed
From: Dwight Engen <dwight.engen@oracle.com>
To: xfs@oss.sgi.com
Subject: [PATCH v8 6/7] xfs: add capability check to free eofblocks ioctl
Date: Thu, 1 Aug 2013 11:30:20 -0400	[thread overview]
Message-ID: <20130801113020.0d43302f@oracle.com> (raw)

Check for CAP_SYS_ADMIN since the caller can truncate preallocated
blocks from files they do not own nor have write access to. A more
fine grained access check was considered: require the caller to
specify their own uid/gid and to use inode_permission to check for
write, but this would not catch the case of an inode not reachable
via path traversal from the callers mount namespace.

Add check for read-only filesystem to free eofblocks ioctl.

Signed-off-by: Dwight Engen <dwight.engen@oracle.com>
---
 fs/xfs/xfs_ioctl.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 60d9d1e..c8f3511 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1620,6 +1620,12 @@ xfs_file_ioctl(
 		struct xfs_fs_eofblocks eofb;
 		struct xfs_eofblocks keofb;
 
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		if (mp->m_flags & XFS_MOUNT_RDONLY)
+			return -XFS_ERROR(EROFS);
+
 		if (copy_from_user(&eofb, arg, sizeof(eofb)))
 			return -XFS_ERROR(EFAULT);
 
-- 
1.8.1.4

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

             reply	other threads:[~2013-08-01 15:30 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-01 15:30 Dwight Engen [this message]
2013-08-01 16:27 ` [PATCH v8 6/7] xfs: add capability check to free eofblocks ioctl Brian Foster
2013-08-02  1:47 ` Dave Chinner
2013-08-02  2:47 ` Gao feng
  -- strict thread matches above, loose matches on Subject: below --
2013-08-15 18:07 [PATCH v8 0/7] userns: Convert xfs to use kuid_t/kgid_t where appropriate Dwight Engen
2013-08-15 18:08 ` [PATCH v8 6/7] xfs: add capability check to free eofblocks ioctl Dwight Engen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20130801113020.0d43302f@oracle.com \
    --to=dwight.engen@oracle.com \
    --cc=xfs@oss.sgi.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox