From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tomas Bortoli , Ian Kent , syzbot+60c837b428dc84e83a93@syzkaller.appspotmail.com, Dmitry Vyukov , Andrew Morton , Linus Torvalds Subject: [PATCH 4.17 072/101] autofs: fix slab out of bounds read in getname_kernel() Date: Fri, 20 Jul 2018 14:14:18 +0200 Message-Id: <20180720121426.364579104@linuxfoundation.org> In-Reply-To: <20180720121422.837870592@linuxfoundation.org> References: <20180720121422.837870592@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tomas Bortoli commit 02f51d45937f7bc7f4dee21e9f85b2d5eac37104 upstream. The autofs subsystem does not check that the "path" parameter is present for all cases where it is required when it is passed in via the "param" struct. In particular it isn't checked for the AUTOFS_DEV_IOCTL_OPENMOUNT_CMD ioctl command. To solve it, modify validate_dev_ioctl(function to check that a path has been provided for ioctl commands that require it. Link: http://lkml.kernel.org/r/153060031527.26631.18306637892746301555.stgit@pluto.themaw.net Signed-off-by: Tomas Bortoli Signed-off-by: Ian Kent Reported-by: syzbot+60c837b428dc84e83a93@syzkaller.appspotmail.com Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/autofs4/dev-ioctl.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -148,6 +148,15 @@ static int validate_dev_ioctl(int cmd, s cmd); goto out; } + } else { + unsigned int inr = _IOC_NR(cmd); + + if (inr == AUTOFS_DEV_IOCTL_OPENMOUNT_CMD || + inr == AUTOFS_DEV_IOCTL_REQUESTER_CMD || + inr == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD) { + err = -EINVAL; + goto out; + } } err = 0; @@ -284,7 +293,8 @@ static int autofs_dev_ioctl_openmount(st dev_t devid; int err, fd; - /* param->path has already been checked */ + /* param->path has been checked in validate_dev_ioctl() */ + if (!param->openmount.devid) return -EINVAL; @@ -446,10 +456,7 @@ static int autofs_dev_ioctl_requester(st dev_t devid; int err = -ENOENT; - if (param->size <= AUTOFS_DEV_IOCTL_SIZE) { - err = -EINVAL; - goto out; - } + /* param->path has been checked in validate_dev_ioctl() */ devid = sbi->sb->s_dev; @@ -534,10 +541,7 @@ static int autofs_dev_ioctl_ismountpoint unsigned int devid, magic; int err = -ENOENT; - if (param->size <= AUTOFS_DEV_IOCTL_SIZE) { - err = -EINVAL; - goto out; - } + /* param->path has been checked in validate_dev_ioctl() */ name = param->path; type = param->ismountpoint.in.type;