From 72ad3b772b6d393701df58ba1359b0bb346a19ed Mon Sep 17 00:00:00 2001 From: Stefan Wahren Date: Thu, 28 Dec 2023 20:39:02 +0100 Subject: [PATCH 1/2] ARM: sun9i: smp: Fix array-index-out-of-bounds read in sunxi_mc_smp_init Running a multi-arch kernel (multi_v7_defconfig) on a Raspberry Pi 3B+ with enabled CONFIG_UBSAN triggers the following warning: UBSAN: array-index-out-of-bounds in arch/arm/mach-sunxi/mc_smp.c:810:29 index 2 is out of range for type 'sunxi_mc_smp_data [2]' CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.7.0-rc6-00248-g5254c0cbc92d Hardware name: BCM2835 unwind_backtrace from show_stack+0x10/0x14 show_stack from dump_stack_lvl+0x40/0x4c dump_stack_lvl from ubsan_epilogue+0x8/0x34 ubsan_epilogue from __ubsan_handle_out_of_bounds+0x78/0x80 __ubsan_handle_out_of_bounds from sunxi_mc_smp_init+0xe4/0x4cc sunxi_mc_smp_init from do_one_initcall+0xa0/0x2fc do_one_initcall from kernel_init_freeable+0xf4/0x2f4 kernel_init_freeable from kernel_init+0x18/0x158 kernel_init from ret_from_fork+0x14/0x28 Since the enabled method couldn't match with any entry from sunxi_mc_smp_data, the value of the index shouldn't be used right after the loop. So move it after the check of ret in order to have a valid index. Fixes: 1631090e34f5 ("ARM: sun9i: smp: Add is_a83t field") Signed-off-by: Stefan Wahren Link: https://lore.kernel.org/r/20231228193903.9078-1-wahrenst@gmx.net Reviewed-by: Chen-Yu Tsai Signed-off-by: Arnd Bergmann --- arch/arm/mach-sunxi/mc_smp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-sunxi/mc_smp.c b/arch/arm/mach-sunxi/mc_smp.c index cb63921232a6..6ec3445f3c72 100644 --- a/arch/arm/mach-sunxi/mc_smp.c +++ b/arch/arm/mach-sunxi/mc_smp.c @@ -807,12 +807,12 @@ static int __init sunxi_mc_smp_init(void) break; } - is_a83t = sunxi_mc_smp_data[i].is_a83t; - of_node_put(node); if (ret) return -ENODEV; + is_a83t = sunxi_mc_smp_data[i].is_a83t; + if (!sunxi_mc_smp_cpu_table_init()) return -EINVAL; From 643fe70e7bcdcc9e2d96952f7fc2bab56385cce5 Mon Sep 17 00:00:00 2001 From: Stefan Wahren Date: Thu, 28 Dec 2023 20:39:03 +0100 Subject: [PATCH 2/2] ARM: sun9i: smp: fix return code check of of_property_match_string of_property_match_string returns an int; either an index from 0 or greater if successful or negative on failure. Even it's very unlikely that the DT CPU node contains multiple enable-methods these checks should be fixed. This patch was inspired by the work of Nick Desaulniers. Link: https://lore.kernel.org/lkml/20230516-sunxi-v1-1-ac4b9651a8c1@google.com/T/ Cc: Nick Desaulniers Signed-off-by: Stefan Wahren Link: https://lore.kernel.org/r/20231228193903.9078-2-wahrenst@gmx.net Reviewed-by: Chen-Yu Tsai Signed-off-by: Arnd Bergmann --- arch/arm/mach-sunxi/mc_smp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-sunxi/mc_smp.c b/arch/arm/mach-sunxi/mc_smp.c index 6ec3445f3c72..277f6aa8e6c2 100644 --- a/arch/arm/mach-sunxi/mc_smp.c +++ b/arch/arm/mach-sunxi/mc_smp.c @@ -803,12 +803,12 @@ static int __init sunxi_mc_smp_init(void) for (i = 0; i < ARRAY_SIZE(sunxi_mc_smp_data); i++) { ret = of_property_match_string(node, "enable-method", sunxi_mc_smp_data[i].enable_method); - if (!ret) + if (ret >= 0) break; } of_node_put(node); - if (ret) + if (ret < 0) return -ENODEV; is_a83t = sunxi_mc_smp_data[i].is_a83t;