linux-kernel - [PATCH 4.11 097/115] xfs: fix over-copying of getbmap parameters from userspace

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20170605153101.480600906@linuxfoundation.org>
Date:   Mon,  5 Jun 2017 18:18:10 +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,
        "Darrick J. Wong" <darrick.wong@...cle.com>,
        Christoph Hellwig <hch@....de>
Subject: [PATCH 4.11 097/115] xfs: fix over-copying of getbmap parameters from userspace

4.11-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Darrick J. Wong <darrick.wong@...cle.com>

commit be6324c00c4d1e0e665f03ed1fc18863a88da119 upstream.

In xfs_ioc_getbmap, we should only copy the fields of struct getbmap
from userspace, or else we end up copying random stack contents into the
kernel.  struct getbmap is a strict subset of getbmapx, so a partial
structure copy should work fine.

Signed-off-by: Darrick J. Wong <darrick.wong@...cle.com>
Reviewed-by: Christoph Hellwig <hch@....de>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 fs/xfs/xfs_ioctl.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1543,10 +1543,11 @@ xfs_ioc_getbmap(
 	unsigned int		cmd,
 	void			__user *arg)
 {
-	struct getbmapx		bmx;
+	struct getbmapx		bmx = { 0 };
 	int			error;

-	if (copy_from_user(&bmx, arg, sizeof(struct getbmapx)))
+	/* struct getbmap is a strict subset of struct getbmapx. */
+	if (copy_from_user(&bmx, arg, offsetof(struct getbmapx, bmv_iflags)))
 		return -EFAULT;

 	if (bmx.bmv_count < 2)