This is a note to let you know that I've just added the patch titled ARM: vexpress/spc: Avoid negative array index when !SMP to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm-vexpress-spc-avoid-negative-array-index-when-smp.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 50836f7b432ef32670bd5fe722d5c9f18ee2fc4e Author: Kees Cook <keescook@xxxxxxxxxxxx> Date: Thu Mar 31 12:04:43 2022 -0700 ARM: vexpress/spc: Avoid negative array index when !SMP [ Upstream commit b3f1dd52c991d79118f35e6d1bf4d7cb09882e38 ] 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. Link: https://lore.kernel.org/r/20220331190443.851661-1-keescook@xxxxxxxxxxxx Cc: Liviu Dudau <liviu.dudau@xxxxxxx> Cc: Sudeep Holla <sudeep.holla@xxxxxxx> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx Acked-by: Liviu Dudau <liviu.dudau@xxxxxxx> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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))