From 85c31887a20da06fe2803b4ec1031b9af89c1899 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Sat, 6 Jan 2018 01:13:08 +0100 Subject: [PATCH] xfrm: don't call xfrm_policy_cache_flush while holding spinlock commit b1bdcb59b64f806ef08d25a85c39ffb3ad841ce6 upstream. xfrm_policy_cache_flush can sleep, so it cannot be called while holding a spinlock. We could release the lock first, but I don't see why we need to invoke this function here in first place, the packet path won't reuse an xdst entry unless its still valid. While at it, add an annotation to xfrm_policy_cache_flush, it would have probably caught this bug sooner. Fixes: ec30d78c14a813 ("xfrm: add xdst pcpu cache") Reported-by: syzbot+e149f7d1328c26f9c12f@syzkaller.appspotmail.com Signed-off-by: Florian Westphal Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman --- net/xfrm/xfrm_policy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 688ed34f0671..27b914000221 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -975,8 +975,6 @@ int xfrm_policy_flush(struct net *net, u8 type, bool task_valid) } if (!cnt) err = -ESRCH; - else - xfrm_policy_cache_flush(); out: spin_unlock_bh(&net->xfrm.xfrm_policy_lock); return err; @@ -1738,6 +1736,8 @@ void xfrm_policy_cache_flush(void) bool found = 0; int cpu; + might_sleep(); + local_bh_disable(); rcu_read_lock(); for_each_possible_cpu(cpu) { -- 2.11.0