Patchwork [net-next] rtnetlink: Fix null-ptr-deref in rtnl_newlink

login
register
mail settings
Submitter Prashant Bhole
Date June 1, 2018, 8:16 a.m.
Message ID <20180601081658.6968-1-bhole_prashant_q7@lab.ntt.co.jp>
Download mbox | patch
Permalink /patch/539259/
State New
Headers show

Comments

Prashant Bhole - June 1, 2018, 8:16 a.m.
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_q7@lab.ntt.co.jp>
---
 net/core/rtnetlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Eric Dumazet - June 1, 2018, 8:26 a.m.
On Fri, Jun 1, 2018 at 4:18 AM Prashant Bhole
<bhole_prashant_q7@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_q7@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.
Ido Schimmel - June 1, 2018, 1:03 p.m.
On Fri, Jun 01, 2018 at 05:16:58PM +0900, Prashant Bhole 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_q7@lab.ntt.co.jp>

My machine crashed while running regression tests. Thanks for fixing!

Tested-by: Ido Schimmel <idosch@mellanox.com>
David Miller - June 1, 2018, 2:39 p.m.
From: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Date: Fri,  1 Jun 2018 17:16:58 +0900

> 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_q7@lab.ntt.co.jp>

Applied, thanks.
Kees Cook - June 1, 2018, 10:13 p.m.
On Fri, Jun 1, 2018 at 1:26 AM, Eric Dumazet <edumazet@google.com> wrote:
> On Fri, Jun 1, 2018 at 4:18 AM Prashant Bhole
> <bhole_prashant_q7@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_q7@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 <keescook@chromium.org>

-Kees

Patch

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;
 
 			if (m_ops->slave_maxtype &&