Hello!
Quoting r. Chris Wright ([EMAIL PROTECTED]) "Re: [PATCH 1/5] compat_ioctl call
seems to miss a security hook":
> * Michael S. Tsirkin ([EMAIL PROTECTED]) wrote:
> > diff -rup linux-2.6.10-orig/fs/compat.c linux-2.6.10-ioctl-sym/fs/compat.c
> > --- linux-2.6.10-orig/fs/compat.c 2005-01-18 10:58:33.609880024 +0200
> > +++ linux-2.6.10-ioctl-sym/fs/compat.c 2005-01-18 10:54:26.289478440
> > +0200
> > @@ -437,6 +437,11 @@ asmlinkage long compat_sys_ioctl(unsigne
> > if (!filp)
> > goto out;
> >
> > + /* RED-PEN how should LSM module know it's handling 32bit? */
> > + error = security_file_ioctl(filp, cmd, arg);
> > + if (error)
> > + goto out_fput;
> > +
>
> This is now called twice in the plain do_ioctl: case. A generic vfs handler
> could alleviate that.
I'm all for it, but the way the patch below works, we could end up
calling ->ioctl or ->unlocked_ioctl from the compat
syscall, and we dont want that.
MST
> ===== fs/ioctl.c 1.15 vs edited =====
> --- 1.15/fs/ioctl.c 2005-01-15 14:31:01 -08:00
> +++ edited/fs/ioctl.c 2005-01-18 11:18:33 -08:00
> @@ -77,21 +77,10 @@ static int file_ioctl(struct file *filp,
> return do_ioctl(filp, cmd, arg);
> }
>
> -
> -asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long
> arg)
> +int vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, unsigned
> long arg)
> {
> - struct file * filp;
> unsigned int flag;
> - int on, error = -EBADF;
> - int fput_needed;
> -
> - filp = fget_light(fd, &fput_needed);
> - if (!filp)
> - goto out;
> -
> - error = security_file_ioctl(filp, cmd, arg);
> - if (error)
> - goto out_fput;
> + int on, error = 0;
>
> switch (cmd) {
> case FIOCLEX:
> @@ -157,6 +146,24 @@ asmlinkage long sys_ioctl(unsigned int f
> error = do_ioctl(filp, cmd, arg);
> break;
> }
> + return error;
> +}
> +
> +asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long
> arg)
> +{
> + struct file * filp;
> + int error = -EBADF;
> + int fput_needed;
> +
> + filp = fget_light(fd, &fput_needed);
> + if (!filp)
> + goto out;
> +
> + error = security_file_ioctl(filp, cmd, arg);
> + if (error)
> + goto out_fput;
> +
> + error = vfs_ioctl(filp, fd, cmd, arg);
> out_fput:
> fput_light(filp, fput_needed);
> out:
> ===== fs/compat.c 1.48 vs edited =====
> --- 1.48/fs/compat.c 2005-01-15 14:31:01 -08:00
> +++ edited/fs/compat.c 2005-01-18 11:07:56 -08:00
> @@ -437,6 +437,11 @@ asmlinkage long compat_sys_ioctl(unsigne
> if (!filp)
> goto out;
>
> + /* RED-PEN how should LSM module know it's handling 32bit? */
> + error = security_file_ioctl(filp, cmd, arg);
> + if (error)
> + goto out_fput;
> +
> if (filp->f_op && filp->f_op->compat_ioctl) {
> error = filp->f_op->compat_ioctl(filp, cmd, arg);
> if (error != -ENOIOCTLCMD)
> @@ -477,7 +482,7 @@ asmlinkage long compat_sys_ioctl(unsigne
>
> up_read(&ioctl32_sem);
> do_ioctl:
> - error = sys_ioctl(fd, cmd, arg);
> + error = vfs_ioctl(filp, fd, cmd, arg);
> out_fput:
> fput_light(filp, fput_needed);
> out:
> ===== include/linux/fs.h 1.373 vs edited =====
> --- 1.373/include/linux/fs.h 2005-01-15 14:31:01 -08:00
> +++ edited/include/linux/fs.h 2005-01-18 11:10:54 -08:00
> @@ -1564,6 +1564,8 @@ extern int vfs_stat(char __user *, struc
> extern int vfs_lstat(char __user *, struct kstat *);
> extern int vfs_fstat(unsigned int, struct kstat *);
>
> +extern int vfs_ioctl(struct file *, unsigned int, unsigned int, unsigned
> long);
> +
> extern struct file_system_type *get_fs_type(const char *name);
> extern struct super_block *get_super(struct block_device *);
> extern struct super_block *user_get_super(dev_t);
-
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