On Monday, September 29, 2014 02:30:29 PM Darren Hart wrote:
> On Mon, Sep 29, 2014 at 03:10:51PM +0200, Pali Rohár wrote:
> > Without this patch driver dell-wmi is trying to access elements of dynamically
> > allocated array without checking array size. This can lead to memory corruption
> > or kernel panic. This patch adds missing checks for array size.
> >
> > Signed-off-by: Pali Rohár <pali.rohar@xxxxxxxxx>
>
> Looks good to me. Rafael, any concerns?
Not anything obvious.
>
> Cc: linux-acpi
Thanks!
> > ---
> > This patch should be probably applied to stable kernel trees as it fixing
> > possible memory corruption.
> > ---
> > drivers/platform/x86/dell-wmi.c | 12 +++++++++---
> > 1 file changed, 9 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
> > index 390e8e3..25721bf 100644
> > --- a/drivers/platform/x86/dell-wmi.c
> > +++ b/drivers/platform/x86/dell-wmi.c
> > @@ -163,18 +163,24 @@ static void dell_wmi_notify(u32 value, void *context)
> > const struct key_entry *key;
> > int reported_key;
> > u16 *buffer_entry = (u16 *)obj->buffer.pointer;
> > + int buffer_size = obj->buffer.length/2;
> >
> > - if (dell_new_hk_type && (buffer_entry[1] != 0x10)) {
> > + if (buffer_size >= 2 && dell_new_hk_type && buffer_entry[1] != 0x10) {
> > pr_info("Received unknown WMI event (0x%x)\n",
> > buffer_entry[1]);
> > kfree(obj);
> > return;
> > }
> >
> > - if (dell_new_hk_type || buffer_entry[1] == 0x0)
> > + if (buffer_size >= 3 && (dell_new_hk_type || buffer_entry[1] == 0x0))
> > reported_key = (int)buffer_entry[2];
> > - else
> > + else if (buffer_size >= 2)
> > reported_key = (int)buffer_entry[1] & 0xffff;
> > + else {
> > + pr_info("Received unknown WMI event\n");
> > + kfree(obj);
> > + return;
> > + }
> >
> > key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev,
> > reported_key);
>
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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