Re: [PATCH] ARM: sunxi: fix return code check of of_property_match_string

From: Florian Fainelli
Date: Tue May 16 2023 - 14:34:20 EST


+William,

On 5/16/23 09:35, ndesaulniers@xxxxxxxxxx wrote:
of_property_match_string returns an int; either an index from 0 or
greater if successful or negative on failure.

Fixes the following splat observed with UBSAN:
[ 0.166489][ T1] UBSAN: array-index-out-of-bounds in arch/arm/mach-sunxi/mc_smp.c:810:29
[ 0.166934][ T1] index 2 is out of range for type 'sunxi_mc_smp_data [2]'
[ 0.167206][ T1] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.4.0-rc2 #1
[ 0.167515][ T1] Hardware name: Generic DT based system
[ 0.167727][ T1] unwind_backtrace from show_stack+0x18/0x1c
[ 0.167979][ T1] show_stack from dump_stack_lvl+0x68/0x90
[ 0.168226][ T1] dump_stack_lvl from ubsan_epilogue+0x8/0x34
[ 0.168474][ T1] ubsan_epilogue from __ubsan_handle_out_of_bounds+0x78/0x80
[ 0.168760][ T1] __ubsan_handle_out_of_bounds from sunxi_mc_smp_init+0xe8/0x574
[ 0.169100][ T1] sunxi_mc_smp_init from do_one_initcall+0x178/0x9c8
[ 0.169364][ T1] do_one_initcall from kernel_init_freeable+0x1dc/0x28c
[ 0.169661][ T1] kernel_init_freeable from kernel_init+0x20/0x164
[ 0.169912][ T1] kernel_init from ret_from_fork+0x14/0x2c

Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

William had a similar fix submitted back in September of last year, but I do not believe it got applied either:

https://lore.kernel.org/r/20220929012944.454613-1-william.zhang@xxxxxxxxxxxx

lore was not able to find it, but above is the message ID, and attached is his original patch.
--
Florian

Attachment: [PATCH] ARM: sun9i: smp: fix out-of-bounds access error - William Zhang <william.zhang@broadcom.com> - 2022-09-28 1829.eml
Description: application/extension-eml