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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Amol Grover <frextrite@gmail.com>,
	James Morris <jmorris@namei.org>, Sasha Levin <sashal@kernel.org>,
	linux-security-module@vger.kernel.org
Subject: [PATCH AUTOSEL 5.8 01/20] device_cgroup: Fix RCU list debugging warning
Date: Mon, 21 Sep 2020 10:40:08 -0400	[thread overview]
Message-ID: <20200921144027.2135390-1-sashal@kernel.org> (raw)

From: Amol Grover <frextrite@gmail.com>

[ Upstream commit bc62d68e2a0a69fcdcf28aca8edb01abf306b698 ]

exceptions may be traversed using list_for_each_entry_rcu()
outside of an RCU read side critical section BUT under the
protection of decgroup_mutex. Hence add the corresponding
lockdep expression to fix the following false-positive
warning:

[    2.304417] =============================
[    2.304418] WARNING: suspicious RCU usage
[    2.304420] 5.5.4-stable #17 Tainted: G            E
[    2.304422] -----------------------------
[    2.304424] security/device_cgroup.c:355 RCU-list traversed in non-reader section!!

Signed-off-by: Amol Grover <frextrite@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/device_cgroup.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 43ab0ad45c1b6..04375df52fc9a 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -354,7 +354,8 @@ static bool match_exception_partial(struct list_head *exceptions, short type,
 {
 	struct dev_exception_item *ex;
 
-	list_for_each_entry_rcu(ex, exceptions, list) {
+	list_for_each_entry_rcu(ex, exceptions, list,
+				lockdep_is_held(&devcgroup_mutex)) {
 		if ((type & DEVCG_DEV_BLOCK) && !(ex->type & DEVCG_DEV_BLOCK))
 			continue;
 		if ((type & DEVCG_DEV_CHAR) && !(ex->type & DEVCG_DEV_CHAR))
-- 
2.25.1


             reply	other threads:[~2020-09-21 14:40 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-21 14:40 Sasha Levin [this message]
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 02/20] ASoC: pcm3168a: ignore 0 Hz settings Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 03/20] ASoC: wm8994: Skip setting of the WM8994_MICBIAS register for WM1811 Sasha Levin
2020-09-21 15:07   ` Mark Brown
2020-09-22 14:25     ` Sasha Levin
2020-09-22 14:42       ` Mark Brown
2020-09-22 17:46         ` Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 04/20] ASoC: wm8994: Ensure the device is resumed in wm89xx_mic_detect functions Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 05/20] ASoC: Intel: bytcr_rt5640: Add quirk for MPMAN Converter9 2-in-1 Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 06/20] clk: versatile: Add of_node_put() before return statement Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 07/20] RISC-V: Take text_mutex in ftrace_init_nop() Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 08/20] i2c: aspeed: Mask IRQ status to relevant bits Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 09/20] s390/init: add missing __init annotations Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 10/20] lockdep: fix order in trace_hardirqs_off_caller() Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 11/20] EDAC/ghes: Check whether the driver is on the safe list correctly Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 12/20] drm/amdkfd: fix a memory leak issue Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 13/20] drm/amd/display: Don't use DRM_ERROR() for DTM add topology Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 14/20] drm/amd/display: update nv1x stutter latencies Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 15/20] drm/amdgpu/dc: Require primary plane to be enabled whenever the CRTC is Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 16/20] drm/amd/display: Don't log hdcp module warnings in dmesg Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 17/20] i2c: core: Call i2c_acpi_install_space_handler() before i2c_acpi_register_devices() Sasha Levin
2020-10-14 11:09   ` Kieran Bingham
2020-10-14 11:23     ` Hans de Goede
2020-10-14 11:52       ` Kieran Bingham
2020-10-14 13:46       ` Hans de Goede
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 18/20] objtool: Fix noreturn detection for ignored functions Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 19/20] i2c: mediatek: Send i2c master code at more than 1MHz Sasha Levin
2020-09-21 14:40 ` [PATCH AUTOSEL 5.8 20/20] riscv: Fix Kendryte K210 device tree Sasha Levin
2020-09-23  0:27   ` Damien Le Moal
2020-09-26 19:42     ` Palmer Dabbelt
2020-09-26 20:51       ` Sasha Levin

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