Re: [PATCH 4.14-stable] xfrm: Fix a race in the xdst pcpu cache.

[Greg KH]

On Wed, Jan 24, 2018 at 09:57:06AM -0500, David Miller wrote:
> From: Steffen Klassert 
> Date: Wed, 24 Jan 2018 10:13:25 +0100
> 
> > commit 76a4201191814a0061cb5c861fafb9ecaa764846 upstream.
> > 
> > We need to run xfrm_resolve_and_create_bundle() with
> > bottom halves off. Otherwise we may reuse an already
> > released dst_enty when the xfrm lookup functions are
> > called from process context.
> > 
> > Fixes: c30d78c14a813db39a647b6a348b428 ("xfrm: add xdst pcpu cache")
> > Reported-by: Darius Ski 
> > Signed-off-by: Steffen Klassert 
> 
> ACK

Thanks, now queued up.

greg k-h

Re: [PATCH 4.14-stable] xfrm: Fix a race in the xdst pcpu cache.

[David Miller]

From: Steffen Klassert 
Date: Wed, 24 Jan 2018 10:13:25 +0100

> commit 76a4201191814a0061cb5c861fafb9ecaa764846 upstream.
> 
> We need to run xfrm_resolve_and_create_bundle() with
> bottom halves off. Otherwise we may reuse an already
> released dst_enty when the xfrm lookup functions are
> called from process context.
> 
> Fixes: c30d78c14a813db39a647b6a348b428 ("xfrm: add xdst pcpu cache")
> Reported-by: Darius Ski 
> Signed-off-by: Steffen Klassert 

ACK

[PATCH 4.14-stable] xfrm: Fix a race in the xdst pcpu cache.

[Steffen Klassert]

commit 76a4201191814a0061cb5c861fafb9ecaa764846 upstream.

We need to run xfrm_resolve_and_create_bundle() with
bottom halves off. Otherwise we may reuse an already
released dst_enty when the xfrm lookup functions are
called from process context.

Fixes: c30d78c14a813db39a647b6a348b428 ("xfrm: add xdst pcpu cache")
Reported-by: Darius Ski 
Signed-off-by: Steffen Klassert 
---
 net/xfrm/xfrm_policy.c | 8 +++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index bc5eae12fb09..bd6b0e7a0ee4 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2063,8 +2063,11 @@ xfrm_bundle_lookup(struct net *net, const struct flowi 
*fl, u16 family, u8 dir,
if (num_xfrms <= 0)
goto make_dummy_bundle;
 
+   local_bh_disable();
xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
- xflo->dst_orig);
+ xflo->dst_orig);
+   local_bh_enable();
+
if (IS_ERR(xdst)) {
err = PTR_ERR(xdst);
if (err != -EAGAIN)
@@ -2151,9 +2154,12 @@ struct dst_entry *xfrm_lookup(struct net *net, struct 
dst_entry *dst_orig,
goto no_transform;
}
 
+   local_bh_disable();
xdst = xfrm_resolve_and_create_bundle(
pols, num_pols, fl,
family, dst_orig);
+   local_bh_enable();
+
if (IS_ERR(xdst)) {
xfrm_pols_put(pols, num_pols);
err = PTR_ERR(xdst);
-- 
2.14.1