diff options
authorHugh Dickins <hugh@veritas.com>2007-05-26 00:39:17 +0100
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-25 17:37:46 -0700
commitf4d43bd579f13219ffd3cae48432eab5bbac2d6f (patch)
parent1ea0975875294964853209927feccdf6bc8cf5f9 (diff)
fix compat console unimap regression
Why is it that since the 2f1a2ccb9c0de632ab07193becf5f7121794f6ae console UTF-8 fixes went into 2.6.22-rc1, the PowerMac G5 shows only inverse video question marks for the text on tty2-6? whereas tty1 is fine, and so is x86. No fault of that patch: by removing the old fallback behaviour, it reveals that 32-bit setfont running on 64-bit kernels has only really worked on the current console, the rest getting faked by that inadequate fallback. Bring the compat do_unimap_ioctl into line with the main one: PIO_UNIMAP and GIO_UNIMAP apply to the specified tty, not redirected to fg_console. Use the same checks, and most particularly, remember to check access_ok: con_set_unimap and con_get_unimap are using __get_user and __put_user. And the compat vt_check should ask for the same capability as the main one, CAP_SYS_TTY_CONFIG rather than CAP_SYS_ADMIN. Added in vt_ioctl's vc_cons_allocated check for safety, though failure may well be impossible. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 25 insertions, 8 deletions
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 65643def3182..6b44cdc96fac 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -1194,6 +1194,7 @@ static int vt_check(struct file *file)
struct tty_struct *tty;
struct inode *inode = file->f_path.dentry->d_inode;
+ struct vc_data *vc;
if (file->f_op->ioctl != tty_ioctl)
return -EINVAL;
@@ -1204,12 +1205,16 @@ static int vt_check(struct file *file)
if (tty->driver->ioctl != vt_ioctl)
return -EINVAL;
+ vc = (struct vc_data *)tty->driver_data;
+ if (!vc_cons_allocated(vc->vc_num)) /* impossible? */
+ return -ENOIOCTLCMD;
* To have permissions to do most of the vt ioctls, we either have
- * to be the owner of the tty, or super-user.
+ * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
- if (current->signal->tty == tty || capable(CAP_SYS_ADMIN))
+ if (current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG))
return 1;
return 0;
@@ -1310,16 +1315,28 @@ static int do_unimap_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg,
struct unimapdesc32 tmp;
struct unimapdesc32 __user *user_ud = compat_ptr(arg);
int perm = vt_check(file);
- if (perm < 0) return perm;
+ struct vc_data *vc;
+ if (perm < 0)
+ return perm;
if (copy_from_user(&tmp, user_ud, sizeof tmp))
return -EFAULT;
+ if (tmp.entries)
+ if (!access_ok(VERIFY_WRITE, compat_ptr(tmp.entries),
+ tmp.entry_ct*sizeof(struct unipair)))
+ return -EFAULT;
+ vc = ((struct tty_struct *)file->private_data)->driver_data;
switch (cmd) {
- if (!perm) return -EPERM;
- return con_set_unimap(vc_cons[fg_console].d, tmp.entry_ct, compat_ptr(tmp.entries));
+ if (!perm)
+ return -EPERM;
+ return con_set_unimap(vc, tmp.entry_ct,
+ compat_ptr(tmp.entries));
- return con_get_unimap(vc_cons[fg_console].d, tmp.entry_ct, &(user_ud->entry_ct), compat_ptr(tmp.entries));
+ if (!perm && fg_console != vc->vc_num)
+ return -EPERM;
+ return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct),
+ compat_ptr(tmp.entries));
return 0;