Commit ed74277b authored by Todd Poynor's avatar Todd Poynor Committed by Greg Kroah-Hartman
Browse files

staging: gasket: always allow root open for write 



Always allow root to open device for writing.

Drop special-casing of ioctl permissions for root vs. owner.

Convert to bool types as appropriate.

Reported-by: default avatarDmitry Torokhov <dtor@chromium.org>
Signed-off-by: default avatarZhongze Hu <frankhu@chromium.org>
Signed-off-by: default avatarTodd Poynor <toddpoynor@google.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 563f3bb5

drivers/staging/gasket/apex_driver.c

+4 −11
Original line number Diff line number Diff line
@@ -140,7 +140,7 @@ static int apex_reset(struct gasket_dev *gasket_dev, uint type); 


static int apex_get_status(struct gasket_dev *gasket_dev);



static uint apex_ioctl_check_permissions(struct file *file, uint cmd);

static bool apex_ioctl_check_permissions(struct file *file, uint cmd);



static long apex_ioctl(struct file *file, uint cmd, ulong arg);
@@ -625,18 +625,11 @@ static bool is_gcb_in_reset(struct gasket_dev *gasket_dev) 
 * @file: File pointer from ioctl.

 * @cmd: ioctl command.

 *

 * Returns 1 if the current user may execute this ioctl, and 0 otherwise.

 * Returns true if the current user may execute this ioctl, and false otherwise.

 */

static uint apex_ioctl_check_permissions(struct file *filp, uint cmd)

static bool apex_ioctl_check_permissions(struct file *filp, uint cmd)

{

	struct gasket_dev *gasket_dev = filp->private_data;

	int root = capable(CAP_SYS_ADMIN);

	int is_owner = gasket_dev->dev_info.ownership.is_owned &&

		       current->tgid == gasket_dev->dev_info.ownership.owner;



	if (root || is_owner)

		return 1;

	return 0;

	return !!(filp->f_mode & FMODE_WRITE);

}



/*

drivers/staging/gasket/gasket_core.c

+5 −3
Original line number Diff line number Diff line
@@ -1072,6 +1072,7 @@ static int gasket_open(struct inode *inode, struct file *filp) 
	char task_name[TASK_COMM_LEN];

	struct gasket_cdev_info *dev_info =

	    container_of(inode->i_cdev, struct gasket_cdev_info, cdev);

	int is_root = capable(CAP_SYS_ADMIN);



	gasket_dev = dev_info->gasket_dev_ptr;

	driver_desc = gasket_dev->internal_desc->driver_desc;
@@ -1085,7 +1086,7 @@ static int gasket_open(struct inode *inode, struct file *filp) 
		"Attempting to open with tgid %u (%s) (f_mode: 0%03o, "

		"fmode_write: %d is_root: %u)",

		current->tgid, task_name, filp->f_mode,

		(filp->f_mode & FMODE_WRITE), capable(CAP_SYS_ADMIN));

		(filp->f_mode & FMODE_WRITE), is_root);



	/* Always allow non-writing accesses. */

	if (!(filp->f_mode & FMODE_WRITE)) {
@@ -1099,8 +1100,9 @@ static int gasket_open(struct inode *inode, struct file *filp) 
		gasket_dev, "Current owner open count (owning tgid %u): %d.",

		ownership->owner, ownership->write_open_count);



	/* Opening a node owned by another TGID is an error (even root.) */

	if (ownership->is_owned && ownership->owner != current->tgid) {

	/* Opening a node owned by another TGID is an error (unless root) */

	if (ownership->is_owned && ownership->owner != current->tgid &&

	    !is_root) {

		gasket_log_error(

			gasket_dev,

			"Process %u is opening a node held by %u.",

drivers/staging/gasket/gasket_ioctl.c

+14 −16
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ 
#define trace_gasket_ioctl_config_coherent_allocator(x, ...)

#endif



static uint gasket_ioctl_check_permissions(struct file *filp, uint cmd);

static bool gasket_ioctl_check_permissions(struct file *filp, uint cmd);

static int gasket_set_event_fd(struct gasket_dev *dev, ulong arg);

static int gasket_read_page_table_size(

	struct gasket_dev *gasket_dev, ulong arg);
@@ -167,12 +167,13 @@ long gasket_is_supported_ioctl(uint cmd) 
 * @filp: File structure pointer describing this node usage session.

 * @cmd: ioctl number to handle.

 *

 * Standard permissions checker.

 * Check permissions for Gasket ioctls.

 * Returns true if the file opener may execute this ioctl, or false otherwise.

 */

static uint gasket_ioctl_check_permissions(struct file *filp, uint cmd)

static bool gasket_ioctl_check_permissions(struct file *filp, uint cmd)

{

	uint alive, root, device_owner;

	fmode_t read, write;

	bool alive;

	bool read, write;

	struct gasket_dev *gasket_dev = (struct gasket_dev *)filp->private_data;



	alive = (gasket_dev->status == GASKET_STATUS_ALIVE);
@@ -183,36 +184,33 @@ static uint gasket_ioctl_check_permissions(struct file *filp, uint cmd) 
			alive, gasket_dev->status);

	}



	root = capable(CAP_SYS_ADMIN);

	read = filp->f_mode & FMODE_READ;

	write = filp->f_mode & FMODE_WRITE;

	device_owner = (gasket_dev->dev_info.ownership.is_owned &&

			current->tgid == gasket_dev->dev_info.ownership.owner);

	read = !!(filp->f_mode & FMODE_READ);

	write = !!(filp->f_mode & FMODE_WRITE);



	switch (cmd) {

	case GASKET_IOCTL_RESET:

	case GASKET_IOCTL_CLEAR_INTERRUPT_COUNTS:

		return root || (write && device_owner);

		return write;



	case GASKET_IOCTL_PAGE_TABLE_SIZE:

	case GASKET_IOCTL_SIMPLE_PAGE_TABLE_SIZE:

	case GASKET_IOCTL_NUMBER_PAGE_TABLES:

		return root || read;

		return read;



	case GASKET_IOCTL_PARTITION_PAGE_TABLE:

	case GASKET_IOCTL_CONFIG_COHERENT_ALLOCATOR:

		return alive && (root || (write && device_owner));

		return alive && write;



	case GASKET_IOCTL_MAP_BUFFER:

	case GASKET_IOCTL_UNMAP_BUFFER:

		return alive && (root || (write && device_owner));

		return alive && write;



	case GASKET_IOCTL_CLEAR_EVENTFD:

	case GASKET_IOCTL_SET_EVENTFD:

		return alive && (root || (write && device_owner));

		return alive && write;

	}



	return 0; /* unknown permissions */

	return false; /* unknown permissions */

}



/*