Messages in this thread | | | Date | Wed, 31 Aug 2022 10:19:13 +0200 | From | Greg KH <> | Subject | Re: [PATCH] tty: vt: Add checks after calling kzalloc |
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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
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