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| author | Nicolas Pitre <nico@fluxnic.net> | 2020-03-29 00:32:42 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-23 16:46:31 +0300 |
| commit | 2717769e204e83e65b8819c5e2ef3e5b6639b270 (patch) | |
| tree | 8086e490f73e49d5c5bb5bb82fb4890ce4d48be6 /drivers/tty | |
| parent | abf42d2f333b21bf8d33b2fbb8a85fa62037ac01 (diff) | |
| download | linux-2717769e204e83e65b8819c5e2ef3e5b6639b270.tar.xz | |
vt: don't hardcode the mem allocation upper bound
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 3272759b1f3c..e5ffed795e4c 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -1207,7 +1207,7 @@ 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) |