lkml.org 
[lkml]   [2022]   [Aug]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] tty: vt: Add checks after calling kzalloc
On Wed, Aug 31, 2022 at 03:57:42PM +0800, Jiasheng Jiang wrote:
> As the potential failure of the memory allocation,
> it should be better to check the return value after
> calling kzalloc and return error if fails.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
> drivers/tty/vt/vt.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> index ae9c926acd6f..a4d59f3a3ce0 100644
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -3519,11 +3519,19 @@ static int __init con_init(void)
>
> for (currcons = 0; currcons < MIN_NR_CONSOLES; currcons++) {
> vc_cons[currcons].d = vc = kzalloc(sizeof(struct vc_data), GFP_NOWAIT);
> + if (!vc) {
> + console_unlock();
> + return -ENOMEM;
> + }
> INIT_WORK(&vc_cons[currcons].SAK_work, vc_SAK);
> tty_port_init(&vc->port);
> visual_init(vc, currcons, 1);
> /* Assuming vc->vc_{cols,rows,screenbuf_size} are sane here. */
> vc->vc_screenbuf = kzalloc(vc->vc_screenbuf_size, GFP_NOWAIT);
> + if (!vc->vc_screenbuf) {
> + console_unlock();
> + return -ENOMEM;
> + }
> vc_init(vc, vc->vc_rows, vc->vc_cols,
> currcons || !vc->vc_sw->con_save_screen);
> }
> --
> 2.25.1
>

This has been attempted many times in the past, sorry. Unless you can
prove that this can actually happen in real life, we are going to leave
these as-is.

Please do not just do random changes like this without actually testing
to see if it is possible to happen.

thanks,

greg k-h

\
 
 \ /
  Last update: 2022-08-31 10:22    [W:0.031 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site