diff options
| author | Eric Biggers <ebiggers@google.com> | 2020-02-24 11:03:26 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-02 17:34:36 +0300 |
| commit | ac7136b9f15740d5f17a017a5febdf875239a3ea (patch) | |
| tree | 4a93c5dd3179645f275f31619178a3dd065d4f72 | |
| parent | 56a5db17b2985e01e0fa425b119bb7586c0ece28 (diff) | |
| download | linux-ac7136b9f15740d5f17a017a5febdf875239a3ea.tar.xz | |
vt: vt_ioctl: remove unnecessary console allocation checks
commit 1aa6e058dd6cd04471b1f21298270014daf48ac9 upstream.
The vc_cons_allocated() checks in vt_ioctl() and vt_compat_ioctl() are
unnecessary because they can only be reached by calling ioctl() on an
open tty, which implies the corresponding virtual console is allocated.
And even if the virtual console *could* be freed concurrently, then
these checks would be broken since they aren't done under console_lock,
and the vc_data is dereferenced before them anyway.
So, remove these unneeded checks to avoid confusion.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200224080326.295046-1-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/vt/vt_ioctl.c | 21 |
1 files changed, 2 insertions, 19 deletions
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c index 09c2c91b1f80..476745cb806c 100644 --- a/drivers/tty/vt/vt_ioctl.c +++ b/drivers/tty/vt/vt_ioctl.c @@ -350,22 +350,13 @@ int vt_ioctl(struct tty_struct *tty, { struct vc_data *vc = tty->driver_data; struct console_font_op op; /* used in multiple places here */ - unsigned int console; + unsigned int console = vc->vc_num; unsigned char ucval; unsigned int uival; void __user *up = (void __user *)arg; int i, perm; int ret = 0; - console = vc->vc_num; - - - if (!vc_cons_allocated(console)) { /* impossible? */ - ret = -ENOIOCTLCMD; - goto out; - } - - /* * To have permissions to do most of the vt ioctls, we either have * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG. @@ -1195,18 +1186,10 @@ long vt_compat_ioctl(struct tty_struct *tty, { struct vc_data *vc = tty->driver_data; struct console_font_op op; /* used in multiple places here */ - unsigned int console; void __user *up = (void __user *)arg; int perm; int ret = 0; - console = vc->vc_num; - - if (!vc_cons_allocated(console)) { /* impossible? */ - ret = -ENOIOCTLCMD; - goto out; - } - /* * To have permissions to do most of the vt ioctls, we either have * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG. @@ -1266,7 +1249,7 @@ long vt_compat_ioctl(struct tty_struct *tty, arg = (unsigned long)compat_ptr(arg); goto fallback; } -out: + return ret; fallback: |