On Fri, Jun 1, 2018 at 1:26 AM, Eric Dumazet <eduma...@google.com> wrote:
> On Fri, Jun 1, 2018 at 4:18 AM Prashant Bhole
> <bhole_prashant...@lab.ntt.co.jp> wrote:
>>
>> In rtnl_newlink(), NULL check is performed on m_ops however member of
>> ops is accessed. Fixed by accessing member of m_ops instead of ops.
>>
>> [ 345.432629] BUG: KASAN: null-ptr-deref in rtnl_newlink+0x400/0x1110
>> [ 345.432629] Read of size 4 at addr 0000000000000088 by task ip/986
>> [ 345.432629]
>> [ 345.432629] CPU: 1 PID: 986 Comm: ip Not tainted 4.17.0-rc6+ #9
>> [ 345.432629] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
>> 1.10.2-1ubuntu1 04/01/2014
>> [ 345.432629] Call Trace:
>> [ 345.432629] dump_stack+0xc6/0x150
>> [ 345.432629] ? dump_stack_print_info.cold.0+0x1b/0x1b
>> [ 345.432629] ? kasan_report+0xb4/0x410
>> [ 345.432629] kasan_report.cold.4+0x8f/0x91
>> [ 345.432629] ? rtnl_newlink+0x400/0x1110
>> [ 345.432629] rtnl_newlink+0x400/0x1110
>> [...]
>>
>> Fixes: ccf8dbcd062a ("rtnetlink: Remove VLA usage")
>> Signed-off-by: Prashant Bhole <bhole_prashant...@lab.ntt.co.jp>
>> ---
>> net/core/rtnetlink.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
>> index 8ca49a0e13fb..9a1ba2015ad8 100644
>> --- a/net/core/rtnetlink.c
>> +++ b/net/core/rtnetlink.c
>> @@ -2936,7 +2936,7 @@ static int rtnl_newlink(struct sk_buff *skb, struct
>> nlmsghdr *nlh,
>> }
>>
>> if (m_ops) {
>> - if (ops->slave_maxtype > RTNL_SLAVE_MAX_TYPE)
>> + if (m_ops->slave_maxtype > RTNL_SLAVE_MAX_TYPE)
>> return -EINVAL;
>
>
> Oh nice
>
> CC Kees Cook.
Argh. Thank you, yes.
Acked-by: Kees Cook <keesc...@chromium.org>
-Kees
--
Kees Cook
Pixel Security
