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From: Kees Cook <keescook@chromium.org>
To: Liviu Dudau <liviu.dudau@arm.com>
Cc: Kees Cook <keescook@chromium.org>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Russell King <linux@armlinux.org.uk>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH] ARM: vexpress/spc: Avoid negative array index when !SMP
Date: Thu, 31 Mar 2022 12:04:43 -0700	[thread overview]
Message-ID: <20220331190443.851661-1-keescook@chromium.org> (raw)

When building multi_v7_defconfig+CONFIG_SMP=n, -Warray-bounds exposes
a couple negative array index accesses:

arch/arm/mach-vexpress/spc.c: In function 've_spc_clk_init':
arch/arm/mach-vexpress/spc.c:583:21: warning: array subscript -1 is below array bounds of 'bool[2]' {aka '_Bool[2]'} [-Warray-bounds]
  583 |   if (init_opp_table[cluster])
      |       ~~~~~~~~~~~~~~^~~~~~~~~
arch/arm/mach-vexpress/spc.c:556:7: note: while referencing 'init_opp_table'
  556 |  bool init_opp_table[MAX_CLUSTERS] = { false };
      |       ^~~~~~~~~~~~~~
arch/arm/mach-vexpress/spc.c:592:18: warning: array subscript -1 is below array bounds of 'bool[2]' {aka '_Bool[2]'} [-Warray-bounds]
  592 |    init_opp_table[cluster] = true;
      |    ~~~~~~~~~~~~~~^~~~~~~~~
arch/arm/mach-vexpress/spc.c:556:7: note: while referencing 'init_opp_table'
  556 |  bool init_opp_table[MAX_CLUSTERS] = { false };
      |       ^~~~~~~~~~~~~~

Skip this logic when built !SMP.

Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/arm/mach-vexpress/spc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-vexpress/spc.c b/arch/arm/mach-vexpress/spc.c
index 1da11bdb1dfb..1c6500c4e6a1 100644
--- a/arch/arm/mach-vexpress/spc.c
+++ b/arch/arm/mach-vexpress/spc.c
@@ -580,7 +580,7 @@ static int __init ve_spc_clk_init(void)
 		}

 		cluster = topology_physical_package_id(cpu_dev->id);
-		if (init_opp_table[cluster])
+		if (cluster < 0 || init_opp_table[cluster])
 			continue;

 		if (ve_init_opp_table(cpu_dev))
--
2.32.0


WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook@chromium.org>
To: Liviu Dudau <liviu.dudau@arm.com>
Cc: Kees Cook <keescook@chromium.org>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Russell King <linux@armlinux.org.uk>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH] ARM: vexpress/spc: Avoid negative array index when !SMP
Date: Thu, 31 Mar 2022 12:04:43 -0700	[thread overview]
Message-ID: <20220331190443.851661-1-keescook@chromium.org> (raw)

When building multi_v7_defconfig+CONFIG_SMP=n, -Warray-bounds exposes
a couple negative array index accesses:

arch/arm/mach-vexpress/spc.c: In function 've_spc_clk_init':
arch/arm/mach-vexpress/spc.c:583:21: warning: array subscript -1 is below array bounds of 'bool[2]' {aka '_Bool[2]'} [-Warray-bounds]
  583 |   if (init_opp_table[cluster])
      |       ~~~~~~~~~~~~~~^~~~~~~~~
arch/arm/mach-vexpress/spc.c:556:7: note: while referencing 'init_opp_table'
  556 |  bool init_opp_table[MAX_CLUSTERS] = { false };
      |       ^~~~~~~~~~~~~~
arch/arm/mach-vexpress/spc.c:592:18: warning: array subscript -1 is below array bounds of 'bool[2]' {aka '_Bool[2]'} [-Warray-bounds]
  592 |    init_opp_table[cluster] = true;
      |    ~~~~~~~~~~~~~~^~~~~~~~~
arch/arm/mach-vexpress/spc.c:556:7: note: while referencing 'init_opp_table'
  556 |  bool init_opp_table[MAX_CLUSTERS] = { false };
      |       ^~~~~~~~~~~~~~

Skip this logic when built !SMP.

Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/arm/mach-vexpress/spc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-vexpress/spc.c b/arch/arm/mach-vexpress/spc.c
index 1da11bdb1dfb..1c6500c4e6a1 100644
--- a/arch/arm/mach-vexpress/spc.c
+++ b/arch/arm/mach-vexpress/spc.c
@@ -580,7 +580,7 @@ static int __init ve_spc_clk_init(void)
 		}

 		cluster = topology_physical_package_id(cpu_dev->id);
-		if (init_opp_table[cluster])
+		if (cluster < 0 || init_opp_table[cluster])
 			continue;

 		if (ve_init_opp_table(cpu_dev))
--
2.32.0


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             reply	other threads:[~2022-03-31 19:04 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-31 19:04 Kees Cook [this message]
2022-03-31 19:04 ` [PATCH] ARM: vexpress/spc: Avoid negative array index when !SMP Kees Cook
2022-04-01  9:28 ` Liviu Dudau
2022-04-01  9:28   ` Liviu Dudau
2022-04-01 10:11   ` Sudeep Holla
2022-04-01 10:11     ` Sudeep Holla
2022-04-01 10:32     ` Liviu Dudau
2022-04-01 10:32       ` Liviu Dudau
2022-04-07 10:14 ` Sudeep Holla
2022-04-07 10:14   ` Sudeep Holla

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