diff options
| author | Nicolas Pitre <nico@fluxnic.net> | 2020-03-28 17:32:42 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-02 17:24:36 +0200 |
| commit | 82f66b9dfa4c42b73a612466fac53d6d11250e9c (patch) | |
| tree | adc59f57cb989c8ad8d217b6b4c18e09d87dc039 /drivers/tty | |
| parent | 97b294d0e86b3544a3c410b77c640beca692724a (diff) | |
vt: don't hardcode the mem allocation upper bound
commit 2717769e204e83e65b8819c5e2ef3e5b6639b270 upstream.
The code in vc_do_resize() bounds the memory allocation size to avoid
exceeding MAX_ORDER down the kzalloc() call chain and generating a
runtime warning triggerable from user space. However, not only is it
unwise to use a literal value here, but MAX_ORDER may also be
configurable based on CONFIG_FORCE_MAX_ZONEORDER.
Let's use KMALLOC_MAX_SIZE instead.
Note that prior commit bb1107f7c605 ("mm, slab: make sure that
KMALLOC_MAX_SIZE will fit into MAX_ORDER") the KMALLOC_MAX_SIZE value
could not be relied upon.
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Cc: <stable@vger.kernel.org> # v4.10+
Link: https://lore.kernel.org/r/nycvar.YSQ.7.76.2003281702410.2671@knanqh.ubzr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/vt/vt.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 46defa3be9a4..8a4e7879a7a6 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -880,7 +880,7 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc, if (new_cols == vc->vc_cols && new_rows == vc->vc_rows) return 0; - if (new_screen_size > (4 << 20)) + if (new_screen_size > KMALLOC_MAX_SIZE) return -EINVAL; newscreen = kzalloc(new_screen_size, GFP_USER); if (!newscreen) |