xfrm: Fix a race in the xdst pcpu cache.

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 <darius.ski@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This commit is contained in:
Steffen Klassert 2018-01-10 12:14:28 +01:00
parent 1e532d2b49
commit 76a4201191
1 changed files with 7 additions and 1 deletions

View File

@ -2063,8 +2063,11 @@ xfrm_bundle_lookup(struct net *net, const struct flowi *fl, u16 family, u8 dir,
if (num_xfrms <= 0) if (num_xfrms <= 0)
goto make_dummy_bundle; goto make_dummy_bundle;
local_bh_disable();
xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family, xdst = xfrm_resolve_and_create_bundle(pols, num_pols, fl, family,
xflo->dst_orig); xflo->dst_orig);
local_bh_enable();
if (IS_ERR(xdst)) { if (IS_ERR(xdst)) {
err = PTR_ERR(xdst); err = PTR_ERR(xdst);
if (err != -EAGAIN) if (err != -EAGAIN)
@ -2151,9 +2154,12 @@ struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
goto no_transform; goto no_transform;
} }
local_bh_disable();
xdst = xfrm_resolve_and_create_bundle( xdst = xfrm_resolve_and_create_bundle(
pols, num_pols, fl, pols, num_pols, fl,
family, dst_orig); family, dst_orig);
local_bh_enable();
if (IS_ERR(xdst)) { if (IS_ERR(xdst)) {
xfrm_pols_put(pols, num_pols); xfrm_pols_put(pols, num_pols);
err = PTR_ERR(xdst); err = PTR_ERR(xdst);