From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
Roman Gushchin <guro@fb.com>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Sasha Levin <sashal@kernel.org>,
netdev@vger.kernel.org, bpf@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 18/25] bpf: Fix preempt_enable_no_resched() abuse
Date: Thu, 16 May 2019 07:40:21 -0400 [thread overview]
Message-ID: <20190516114029.8682-18-sashal@kernel.org> (raw)
In-Reply-To: <20190516114029.8682-1-sashal@kernel.org>
From: Peter Zijlstra <peterz@infradead.org>
[ Upstream commit 0edd6b64d1939e9e9168ff27947995bb7751db5d ]
Unless the very next line is schedule(), or implies it, one must not use
preempt_enable_no_resched(). It can cause a preemption to go missing and
thereby cause arbitrary delays, breaking the PREEMPT=y invariant.
Cc: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/bpf.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 523481a3471b5..fd95f2efe5f32 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -400,7 +400,7 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
} \
_out: \
rcu_read_unlock(); \
- preempt_enable_no_resched(); \
+ preempt_enable(); \
_ret; \
})
--
2.20.1
next prev parent reply other threads:[~2019-05-16 11:45 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-16 11:40 [PATCH AUTOSEL 4.19 01/25] xfrm: policy: Fix out-of-bound array accesses in __xfrm_policy_unlink Sasha Levin
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 02/25] xfrm6_tunnel: Fix potential panic when unloading xfrm6_tunnel module Sasha Levin
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 03/25] vti4: ipip tunnel deregistration fixes Sasha Levin
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 04/25] xfrm: clean up xfrm protocol checks Sasha Levin
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 05/25] esp4: add length check for UDP encapsulation Sasha Levin
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 06/25] xfrm: Honor original L3 slave device in xfrmi policy lookup Sasha Levin
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 07/25] xfrm4: Fix uninitialized memory read in _decode_session4 Sasha Levin
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 14/25] mac80211: Fix kernel panic due to use of txq after free Sasha Levin
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 15/25] net: ieee802154: fix missing checks for regmap_update_bits Sasha Levin
2019-05-16 11:40 ` Sasha Levin [this message]
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 19/25] qmi_wwan: new Wistron, ZTE and D-Link devices Sasha Levin
2019-05-16 11:40 ` [PATCH AUTOSEL 4.19 20/25] iwlwifi: mvm: check for length correctness in iwl_mvm_create_skb() Sasha Levin
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