This is a note to let you know that I've just added the patch titled
vt: don't hardcode the mem allocation upper bound
to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 2717769e204e83e65b8819c5e2ef3e5b6639b270 Mon Sep 17 00:00:00 2001
From: Nicolas Pitre nico@fluxnic.net Date: Sat, 28 Mar 2020 17:32:42 -0400 Subject: 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 --- drivers/tty/vt/vt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
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)