Family of src/dst can be different from family of selector src/dst.
Use xfrm selector family to validate address prefix length,
while verifying new sa from userspace.
Validated patch with this command:
ip xfrm state add src 1.1.6.1 dst 1.1.6.2 proto esp spi 4260196 \
reqid 20004 mode tunnel aead "rfc4106(gcm(aes))" \
0x1111016400000000000000000000000044440001 128 \
sel src 1011:1:4::2/128 sel dst 1021:1:4::2/128 dev Port5
Fixes: 07bf7908950a ("xfrm: Validate address prefix lengths in the xfrm selector.")
Signed-off-by: Anirudh Gupta <[email protected]>
---
net/xfrm/xfrm_user.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index eb8d14389601..fc2a8c08091b 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -149,7 +149,7 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
int err;
err = -EINVAL;
- switch (p->family) {
+ switch (p->sel.family) {
case AF_INET:
if (p->sel.prefixlen_d > 32 || p->sel.prefixlen_s > 32)
goto out;
--
2.19.0
On Mon, May 20, 2019 at 03:01:56PM +0530, Anirudh Gupta wrote:
>
> diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
> index eb8d14389601..fc2a8c08091b 100644
> --- a/net/xfrm/xfrm_user.c
> +++ b/net/xfrm/xfrm_user.c
> @@ -149,7 +149,7 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
> int err;
>
> err = -EINVAL;
> - switch (p->family) {
> + switch (p->sel.family) {
> case AF_INET:
> if (p->sel.prefixlen_d > 32 || p->sel.prefixlen_s > 32)
> goto out;
You just removed the only verification of p->family...
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
Hi Herbert,
Yes, I notice that is the only verification of p->family from userspace.
However, the underlying conditions added in commit '07bf7908950a',
validates the selector src/dest prefix len.
So, In case when adding a new SA entry, the family of Selector src/dst
is IPv6 and state id src/dst family is IPv4.
Then, the IPv6 selector prefix verification falls in IPv4 switch case.
This results in not being able to provide prefix length of more than
32, even for IPv6 src/dst.
The above mentioned behaviour can easily be reproduced using below
command having IPv6 selector src/dst with greater than 32 prefix
length.
ip xfrm state add src 1.1.6.1 dst 1.1.6.2 proto esp spi 4260196 \
reqid 20004 mode tunnel aead "rfc4106(gcm(aes))" \
0x1111016400000000000000000000000044440001 128 \
sel src 1011:1:4::2/128 sel dst 1021:1:4::2/128 dev Port5
Please let me know, if I fail to explain my point or I am overlooking anything.
Thanks & Regards,
Anirudh
On Mon, May 20, 2019 at 9:02 PM Herbert Xu <[email protected]> wrote:
>
> On Mon, May 20, 2019 at 03:01:56PM +0530, Anirudh Gupta wrote:
> >
> > diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
> > index eb8d14389601..fc2a8c08091b 100644
> > --- a/net/xfrm/xfrm_user.c
> > +++ b/net/xfrm/xfrm_user.c
> > @@ -149,7 +149,7 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
> > int err;
> >
> > err = -EINVAL;
> > - switch (p->family) {
> > + switch (p->sel.family) {
> > case AF_INET:
> > if (p->sel.prefixlen_d > 32 || p->sel.prefixlen_s > 32)
> > goto out;
>
> You just removed the only verification of p->family...
> --
> Email: Herbert Xu <[email protected]>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
Regards
Anirudh Gupta
On Mon, May 20, 2019 at 10:30:29PM +0530, Anirudh Gupta wrote:
> Yes, I notice that is the only verification of p->family from userspace.
> However, the underlying conditions added in commit '07bf7908950a',
> validates the selector src/dest prefix len.
You need to check both p->family and p->sel.family.
Cheers,
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt