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-rw-r--r--drivers/char/pty.c6
-rw-r--r--drivers/char/tty_io.c84
-rw-r--r--fs/internal.h2
-rw-r--r--include/linux/fs.h2
-rw-r--r--include/linux/tty.h8
-rw-r--r--security/selinux/hooks.c5
6 files changed, 69 insertions, 38 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index 2c64faa8efa4..c350d01716bd 100644
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -675,12 +675,8 @@ static int ptmx_open(struct inode *inode, struct file *filp)
}
set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
- filp->private_data = tty;
- file_sb_list_del(filp); /* __dentry_open has put it on the sb list */
- spin_lock(&tty_files_lock);
- list_add(&filp->f_u.fu_list, &tty->tty_files);
- spin_unlock(&tty_files_lock);
+ tty_add_file(tty, filp);
retval = devpts_pty_new(inode, tty->link);
if (retval)
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index cd5b829634ea..949067a0bd47 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -188,6 +188,41 @@ void free_tty_struct(struct tty_struct *tty)
kfree(tty);
}
+static inline struct tty_struct *file_tty(struct file *file)
+{
+ return ((struct tty_file_private *)file->private_data)->tty;
+}
+
+/* Associate a new file with the tty structure */
+void tty_add_file(struct tty_struct *tty, struct file *file)
+{
+ struct tty_file_private *priv;
+
+ /* XXX: must implement proper error handling in callers */
+ priv = kmalloc(sizeof(*priv), GFP_KERNEL|__GFP_NOFAIL);
+
+ priv->tty = tty;
+ priv->file = file;
+ file->private_data = priv;
+
+ spin_lock(&tty_files_lock);
+ list_add(&priv->list, &tty->tty_files);
+ spin_unlock(&tty_files_lock);
+}
+
+/* Delete file from its tty */
+void tty_del_file(struct file *file)
+{
+ struct tty_file_private *priv = file->private_data;
+
+ spin_lock(&tty_files_lock);
+ list_del(&priv->list);
+ spin_unlock(&tty_files_lock);
+ file->private_data = NULL;
+ kfree(priv);
+}
+
+
#define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base)
/**
@@ -500,6 +535,7 @@ void __tty_hangup(struct tty_struct *tty)
struct file *cons_filp = NULL;
struct file *filp, *f = NULL;
struct task_struct *p;
+ struct tty_file_private *priv;
int closecount = 0, n;
unsigned long flags;
int refs = 0;
@@ -509,7 +545,7 @@ void __tty_hangup(struct tty_struct *tty)
spin_lock(&redirect_lock);
- if (redirect && redirect->private_data == tty) {
+ if (redirect && file_tty(redirect) == tty) {
f = redirect;
redirect = NULL;
}
@@ -524,7 +560,8 @@ void __tty_hangup(struct tty_struct *tty)
spin_lock(&tty_files_lock);
/* This breaks for file handles being sent over AF_UNIX sockets ? */
- list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) {
+ list_for_each_entry(priv, &tty->tty_files, list) {
+ filp = priv->file;
if (filp->f_op->write == redirected_tty_write)
cons_filp = filp;
if (filp->f_op->write != tty_write)
@@ -892,12 +929,10 @@ static ssize_t tty_read(struct file *file, char __user *buf, size_t count,
loff_t *ppos)
{
int i;
- struct tty_struct *tty;
- struct inode *inode;
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct tty_struct *tty = file_tty(file);
struct tty_ldisc *ld;
- tty = file->private_data;
- inode = file->f_path.dentry->d_inode;
if (tty_paranoia_check(tty, inode, "tty_read"))
return -EIO;
if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags)))
@@ -1068,12 +1103,11 @@ void tty_write_message(struct tty_struct *tty, char *msg)
static ssize_t tty_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
- struct tty_struct *tty;
struct inode *inode = file->f_path.dentry->d_inode;
+ struct tty_struct *tty = file_tty(file);
+ struct tty_ldisc *ld;
ssize_t ret;
- struct tty_ldisc *ld;
- tty = file->private_data;
if (tty_paranoia_check(tty, inode, "tty_write"))
return -EIO;
if (!tty || !tty->ops->write ||
@@ -1510,13 +1544,13 @@ static void release_tty(struct tty_struct *tty, int idx)
int tty_release(struct inode *inode, struct file *filp)
{
- struct tty_struct *tty, *o_tty;
+ struct tty_struct *tty = file_tty(filp);
+ struct tty_struct *o_tty;
int pty_master, tty_closing, o_tty_closing, do_sleep;
int devpts;
int idx;
char buf[64];
- tty = filp->private_data;
if (tty_paranoia_check(tty, inode, "tty_release_dev"))
return 0;
@@ -1674,11 +1708,7 @@ int tty_release(struct inode *inode, struct file *filp)
* - do_tty_hangup no longer sees this file descriptor as
* something that needs to be handled for hangups.
*/
- spin_lock(&tty_files_lock);
- BUG_ON(list_empty(&filp->f_u.fu_list));
- list_del_init(&filp->f_u.fu_list);
- spin_unlock(&tty_files_lock);
- filp->private_data = NULL;
+ tty_del_file(filp);
/*
* Perform some housekeeping before deciding whether to return.
@@ -1845,12 +1875,8 @@ got_driver:
return PTR_ERR(tty);
}
- filp->private_data = tty;
- BUG_ON(list_empty(&filp->f_u.fu_list));
- file_sb_list_del(filp); /* __dentry_open has put it on the sb list */
- spin_lock(&tty_files_lock);
- list_add(&filp->f_u.fu_list, &tty->tty_files);
- spin_unlock(&tty_files_lock);
+ tty_add_file(tty, filp);
+
check_tty_count(tty, "tty_open");
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
tty->driver->subtype == PTY_TYPE_MASTER)
@@ -1926,11 +1952,10 @@ got_driver:
static unsigned int tty_poll(struct file *filp, poll_table *wait)
{
- struct tty_struct *tty;
+ struct tty_struct *tty = file_tty(filp);
struct tty_ldisc *ld;
int ret = 0;
- tty = filp->private_data;
if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll"))
return 0;
@@ -1943,11 +1968,10 @@ static unsigned int tty_poll(struct file *filp, poll_table *wait)
static int __tty_fasync(int fd, struct file *filp, int on)
{
- struct tty_struct *tty;
+ struct tty_struct *tty = file_tty(filp);
unsigned long flags;
int retval = 0;
- tty = filp->private_data;
if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync"))
goto out;
@@ -2501,13 +2525,13 @@ EXPORT_SYMBOL(tty_pair_get_pty);
*/
long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
- struct tty_struct *tty, *real_tty;
+ struct tty_struct *tty = file_tty(file);
+ struct tty_struct *real_tty;
void __user *p = (void __user *)arg;
int retval;
struct tty_ldisc *ld;
struct inode *inode = file->f_dentry->d_inode;
- tty = file->private_data;
if (tty_paranoia_check(tty, inode, "tty_ioctl"))
return -EINVAL;
@@ -2629,7 +2653,7 @@ static long tty_compat_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct inode *inode = file->f_dentry->d_inode;
- struct tty_struct *tty = file->private_data;
+ struct tty_struct *tty = file_tty(file);
struct tty_ldisc *ld;
int retval = -ENOIOCTLCMD;
@@ -2721,7 +2745,7 @@ void __do_SAK(struct tty_struct *tty)
if (!filp)
continue;
if (filp->f_op->read == tty_read &&
- filp->private_data == tty) {
+ file_tty(filp) == tty) {
printk(KERN_NOTICE "SAK: killed process %d"
" (%s): fd#%d opened to the tty\n",
task_pid_nr(p), p->comm, i);
diff --git a/fs/internal.h b/fs/internal.h
index 6b706bc60a66..6a5c13a80660 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -80,6 +80,8 @@ extern void chroot_fs_refs(struct path *, struct path *);
/*
* file_table.c
*/
+extern void file_sb_list_add(struct file *f, struct super_block *sb);
+extern void file_sb_list_del(struct file *f);
extern void mark_files_ro(struct super_block *);
extern struct file *get_empty_filp(void);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5a9a9e5a3705..5e65add0f163 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2185,8 +2185,6 @@ static inline void insert_inode_hash(struct inode *inode) {
__insert_inode_hash(inode, inode->i_ino);
}
-extern void file_sb_list_add(struct file *f, struct super_block *sb);
-extern void file_sb_list_del(struct file *f);
#ifdef CONFIG_BLOCK
extern void submit_bio(int, struct bio *);
extern int bdev_read_only(struct block_device *);
diff --git a/include/linux/tty.h b/include/linux/tty.h
index f6b371a2514e..67d64e6efe7a 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -329,6 +329,13 @@ struct tty_struct {
struct tty_port *port;
};
+/* Each of a tty's open files has private_data pointing to tty_file_private */
+struct tty_file_private {
+ struct tty_struct *tty;
+ struct file *file;
+ struct list_head list;
+};
+
/* tty magic number */
#define TTY_MAGIC 0x5401
@@ -458,6 +465,7 @@ extern void proc_clear_tty(struct task_struct *p);
extern struct tty_struct *get_current_tty(void);
extern void tty_default_fops(struct file_operations *fops);
extern struct tty_struct *alloc_tty_struct(void);
+extern void tty_add_file(struct tty_struct *tty, struct file *file);
extern void free_tty_struct(struct tty_struct *tty);
extern void initialize_tty_struct(struct tty_struct *tty,
struct tty_driver *driver, int idx);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index bd7da0f0ccf3..4796ddd4e721 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2172,6 +2172,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
if (tty) {
spin_lock(&tty_files_lock);
if (!list_empty(&tty->tty_files)) {
+ struct tty_file_private *file_priv;
struct inode *inode;
/* Revalidate access to controlling tty.
@@ -2179,7 +2180,9 @@ static inline void flush_unauthorized_files(const struct cred *cred,
than using file_has_perm, as this particular open
file may belong to another process and we are only
interested in the inode-based check here. */
- file = list_first_entry(&tty->tty_files, struct file, f_u.fu_list);
+ file_priv = list_first_entry(&tty->tty_files,
+ struct tty_file_private, list);
+ file = file_priv->file;
inode = file->f_path.dentry->d_inode;
if (inode_has_perm(cred, inode,
FILE__READ | FILE__WRITE, NULL)) {
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.