4.17-stable review patch. If anyone has any objections, please let me know.
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From: Tomas Bortoli tomasbortoli@gmail.com
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... Signed-off-by: Tomas Bortoli tomasbortoli@gmail.com Signed-off-by: Ian Kent raven@themaw.net Reported-by: syzbot+60c837b428dc84e83a93@syzkaller.appspotmail.com Cc: Dmitry Vyukov dvyukov@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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;