This is a note to let you know that I've just added the patch titled
xfrm: don't call xfrm_policy_cache_flush while holding spinlock
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: xfrm-don-t-call-xfrm_policy_cache_flush-while-holding-spinlock.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From b1bdcb59b64f806ef08d25a85c39ffb3ad841ce6 Mon Sep 17 00:00:00 2001
From: Florian Westphal fw@strlen.de Date: Sat, 6 Jan 2018 01:13:08 +0100 Subject: xfrm: don't call xfrm_policy_cache_flush while holding spinlock
From: Florian Westphal fw@strlen.de
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 fw@strlen.de Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/xfrm/xfrm_policy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -975,8 +975,6 @@ int xfrm_policy_flush(struct net *net, u } 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) {
Patches currently in stable-queue which might be from fw@strlen.de are
queue-4.14/xfrm-skip-policies-marked-as-dead-while-rehashing.patch queue-4.14/netfilter-x_tables-avoid-out-of-bounds-reads-in-xt_request_find_-match-target.patch queue-4.14/netfilter-on-sockopt-acquire-sock-lock-only-in-the-required-scope.patch queue-4.14/netfilter-xt_rateest-acquire-xt_rateest_mutex-for-hash-insert.patch queue-4.14/xfrm-don-t-call-xfrm_policy_cache_flush-while-holding-spinlock.patch