Messages in this thread | | | Date | Tue, 22 Feb 2022 09:00:08 +0100 | Subject | Re: [PATCH v1] vt_ioctl: fix potential spectre v1 in VT_DISALLOCATE | From | Jiri Slaby <> |
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On 22. 02. 22, 8:39, Xiaomeng Tong wrote: > In VT_ACTIVATE an almost identical code path has been patched > with array_index_nospec. In the VT_DISALLOCATE path, the arg is > the user input from a system call argument and lately used as a index > for vc_cons[index].d access, which can be reached through path like > vt_disallocate->vc_busy or vt_disallocate->vc_deallocate. > For consistency both code paths should have the same mitigations > applied. Also, the code style is adjusted as suggested by Jiri. > > Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
> --- > drivers/tty/vt/vt_ioctl.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c > index 580136986..8c685b501 100644 > --- a/drivers/tty/vt/vt_ioctl.c > +++ b/drivers/tty/vt/vt_ioctl.c > @@ -898,11 +898,13 @@ int vt_ioctl(struct tty_struct *tty, > if (arg > MAX_NR_CONSOLES) > return -ENXIO; > > - if (arg == 0) > + if (arg == 0) { > vt_disallocate_all(); > - else > - return vt_disallocate(--arg); > - break; > + break; > + } > + > + arg = array_index_nospec(arg - 1, MAX_NR_CONSOLES); > + return vt_disallocate(arg); > > case VT_RESIZE: > {
-- js suse labs
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