From f85daf0e725358be78dfd208dea5fd665d8cb901 Mon Sep 17 00:00:00 2001 From: Hangyu Hua Date: Wed, 1 Jun 2022 14:46:25 +0800 Subject: xfrm: xfrm_policy: fix a possible double xfrm_pols_put() in xfrm_bundle_lookup() xfrm_policy_lookup() will call xfrm_pol_hold_rcu() to get a refcount of pols[0]. This refcount can be dropped in xfrm_expand_policies() when xfrm_expand_policies() return error. pols[0]'s refcount is balanced in here. But xfrm_bundle_lookup() will also call xfrm_pols_put() with num_pols == 1 to drop this refcount when xfrm_expand_policies() return error. This patch also fix an illegal address access. pols[0] will save a error point when xfrm_policy_lookup fails. This lead to xfrm_pols_put to resolve an illegal address in xfrm_bundle_lookup's error path. Fix these by setting num_pols = 0 in xfrm_expand_policies()'s error path. Fixes: 80c802f3073e ("xfrm: cache bundles instead of policies for outgoing flows") Signed-off-by: Hangyu Hua Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_policy.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'net/xfrm') diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index f1876ea61fdc..f1a0bab920a5 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -2678,8 +2678,10 @@ static int xfrm_expand_policies(const struct flowi *fl, u16 family, *num_xfrms = 0; return 0; } - if (IS_ERR(pols[0])) + if (IS_ERR(pols[0])) { + *num_pols = 0; return PTR_ERR(pols[0]); + } *num_xfrms = pols[0]->xfrm_nr; @@ -2694,6 +2696,7 @@ static int xfrm_expand_policies(const struct flowi *fl, u16 family, if (pols[1]) { if (IS_ERR(pols[1])) { xfrm_pols_put(pols, *num_pols); + *num_pols = 0; return PTR_ERR(pols[1]); } (*num_pols)++; -- cgit v1.2.3