From 3dd8f7c3b78b9556582fd64bf5c9986723f9dca1 Mon Sep 17 00:00:00 2001 From: Ian Kent Date: Fri, 8 Sep 2017 16:16:30 -0700 Subject: [PATCH] autofs: make dev ioctl version and ismountpoint user accessible Some of the autofs miscellaneous device ioctls need to be accessable to user space applications without CAP_SYS_ADMIN to get information about autofs mounts. Link: http://lkml.kernel.org/r/150216642517.11652.2338933266137331637.stgit@pluto.themaw.net Signed-off-by: Ian Kent Cc: Colin Walters Cc: Ondrej Holy Cc: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/autofs4/dev-ioctl.c | 12 ++++++++---- include/uapi/linux/auto_dev-ioctl.h | 2 +- 2 files changed, 9 insertions(+), 5 deletions(-) diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index 218a4ecc75cc..ea8b3a1cddd2 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -628,10 +628,6 @@ static int _autofs_dev_ioctl(unsigned int command, ioctl_fn fn = NULL; int err = 0; - /* only root can play with this */ - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST); cmd = _IOC_NR(command); @@ -640,6 +636,14 @@ static int _autofs_dev_ioctl(unsigned int command, return -ENOTTY; } + /* Only root can use ioctls other than AUTOFS_DEV_IOCTL_VERSION_CMD + * and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD + */ + if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD && + cmd != AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD && + !capable(CAP_SYS_ADMIN)) + return -EPERM; + /* Copy the parameters into kernel space. */ param = copy_dev_ioctl(user); if (IS_ERR(param)) diff --git a/include/uapi/linux/auto_dev-ioctl.h b/include/uapi/linux/auto_dev-ioctl.h index 744b3d060968..5558db8e6646 100644 --- a/include/uapi/linux/auto_dev-ioctl.h +++ b/include/uapi/linux/auto_dev-ioctl.h @@ -16,7 +16,7 @@ #define AUTOFS_DEVICE_NAME "autofs" #define AUTOFS_DEV_IOCTL_VERSION_MAJOR 1 -#define AUTOFS_DEV_IOCTL_VERSION_MINOR 0 +#define AUTOFS_DEV_IOCTL_VERSION_MINOR 1 #define AUTOFS_DEV_IOCTL_SIZE sizeof(struct autofs_dev_ioctl) -- 2.20.1