From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scotty Subject: [PATCH] dm ioctl: Access user-land memory through safe functions. Date: Tue, 1 Dec 2015 11:11:04 -0700 Message-ID: <565DE2B8.7040709@eng.utah.edu> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------080605030004010507040202" Return-path: Sender: linux-kernel-owner@vger.kernel.org To: agk@redhat.com, snitzer@redhat.com Cc: linux-kernel@vger.kernel.org, dm-devel@redhat.com List-Id: dm-devel.ids This is a multi-part message in MIME format. --------------080605030004010507040202 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit --------------080605030004010507040202 Content-Type: text/x-patch; name="0001-dm-ioctl-Access-user-land-memory-through-safe-functi.patch" Content-Transfer-Encoding: quoted-printable Content-Disposition: attachment; filename*0="0001-dm-ioctl-Access-user-land-memory-through-safe-functi.pa"; filename*1="tch" =46rom b26adf880eba03ac6f2b1dd87426bb96fd2a0282 Mon Sep 17 00:00:00 2001 From: Scotty Bauer Date: Tue, 1 Dec 2015 10:52:46 -0700 Subject: [PATCH] dm ioctl: Access user-land memory through safe functions= =2E This patch fixes a user-land dereference. Now we use the safe copy_from_user to access the memory. Signed-off-by: Scotty Bauer --- drivers/md/dm-ioctl.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 80a4395..39a9d1a 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1642,9 +1642,13 @@ static ioctl_fn lookup_ioctl(unsigned int cmd, int= *ioctl_flags) static int check_version(unsigned int cmd, struct dm_ioctl __user *user)= { uint32_t version[3]; + uint32_t __user *version_ptr; int r =3D 0; =20 - if (copy_from_user(version, user->version, sizeof(version))) + if (copy_from_user(&version_ptr, &user->version, sizeof(version_ptr))) + return -EFAULT; + + if (copy_from_user(version, version_ptr, sizeof(version))) return -EFAULT; =20 if ((DM_VERSION_MAJOR !=3D version[0]) || @@ -1663,7 +1667,7 @@ static int check_version(unsigned int cmd, struct d= m_ioctl __user *user) version[0] =3D DM_VERSION_MAJOR; version[1] =3D DM_VERSION_MINOR; version[2] =3D DM_VERSION_PATCHLEVEL; - if (copy_to_user(user->version, version, sizeof(version))) + if (copy_to_user(version_ptr, version, sizeof(version))) return -EFAULT; =20 return r; --=20 1.9.1 --------------080605030004010507040202--