Messages in this thread | | | Date | Mon, 25 Mar 2019 12:01:04 +0200 | From | Mika Westerberg <> | Subject | Re: [PATCH] thunderbolt: property: fix a buffer overflow and a missing check |
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On Sun, Mar 24, 2019 at 05:49:16PM -0500, Kangjie Lu wrote: > First, no memory is allocated for "property->value.text"; the > following strcpy will lead to a buffer overflow.
It is actually member of union so assigning via value.txt or value.data is the same.
So no buffer overflow.
> Second, no check is enforced for the return value of kzalloc, > which may lead to NULL-pointer dereference.
Yes, this is valid.
Can you fix the changelog accordingly and resend?
> > The patch fixes the two issues. > > Signed-off-by: Kangjie Lu <kjlu@umn.edu> > --- > drivers/thunderbolt/property.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/thunderbolt/property.c b/drivers/thunderbolt/property.c > index 841314deb446..d5b0cdb8f0b1 100644 > --- a/drivers/thunderbolt/property.c > +++ b/drivers/thunderbolt/property.c > @@ -587,7 +587,12 @@ int tb_property_add_text(struct tb_property_dir *parent, const char *key, > return -ENOMEM; > > property->length = size / 4; > - property->value.data = kzalloc(size, GFP_KERNEL); > + property->value.text = kzalloc(size, GFP_KERNEL); > + if (!property->value.text) { > + kfree(property); > + return -ENOMEM; > + } > + > strcpy(property->value.text, text); > > list_add_tail(&property->list, &parent->properties); > -- > 2.17.1
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