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 5.0 23/34] bpf: Fix preempt_enable_no_resched() abuse
Date: Thu, 16 May 2019 07:39:20 -0400 [thread overview]
Message-ID: <20190516113932.8348-23-sashal@kernel.org> (raw)
In-Reply-To: <20190516113932.8348-1-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 e734f163bd0b9..1fbd7672e4b37 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -455,7 +455,7 @@ 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 11:47 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-16 11:38 [PATCH AUTOSEL 5.0 01/34] xfrm: policy: Fix out-of-bound array accesses in __xfrm_policy_unlink Sasha Levin
2019-05-16 11:38 ` [PATCH AUTOSEL 5.0 02/34] xfrm: Reset secpath in xfrm failure Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 03/34] xfrm6_tunnel: Fix potential panic when unloading xfrm6_tunnel module Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 04/34] vti4: ipip tunnel deregistration fixes Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 05/34] xfrm: clean up xfrm protocol checks Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 06/34] esp4: add length check for UDP encapsulation Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 07/34] xfrm: Honor original L3 slave device in xfrmi policy lookup Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 08/34] xfrm4: Fix uninitialized memory read in _decode_session4 Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 18/34] mac80211: Fix kernel panic due to use of txq after free Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 19/34] net: ieee802154: fix missing checks for regmap_update_bits Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 22/34] tools: bpftool: fix infinite loop in map create Sasha Levin
2019-05-16 11:39 ` Sasha Levin [this message]
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 24/34] qmi_wwan: new Wistron, ZTE and D-Link devices Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 25/34] iwlwifi: mvm: check for length correctness in iwl_mvm_create_skb() Sasha Levin
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