[PATCH V2 1/2] ARM: sun9i: smp: Fix array-index-out-of-bounds read in sunxi_mc_smp_init
Stefan Wahren
wahrenst at gmx.net
Thu Dec 28 11:39:02 PST 2023
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 <wahrenst at gmx.net>
---
Changes in V2:
- append another patch to fix return code check
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;
--
2.34.1
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