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author | Hugh Dickins <hugh@veritas.com> | 2007-05-26 00:39:17 +0100 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-25 17:37:46 -0700 |
commit | f4d43bd579f13219ffd3cae48432eab5bbac2d6f (patch) | |
tree | b3376f267b2e519506633d0bdf73b8cb6d90a981 /fs | |
parent | 1ea0975875294964853209927feccdf6bc8cf5f9 (diff) | |
download | linux-stable-f4d43bd579f13219ffd3cae48432eab5bbac2d6f.tar.gz linux-stable-f4d43bd579f13219ffd3cae48432eab5bbac2d6f.tar.bz2 linux-stable-f4d43bd579f13219ffd3cae48432eab5bbac2d6f.zip |
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>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/compat_ioctl.c | 33 |
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) { case PIO_UNIMAP: - 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)); case GIO_UNIMAP: - 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; } |