Re: [PATCH v4] hw/gpio/aspeed: Add reg_table_count to AspeedGPIOClass

[Andrew Jeffery <andrew@codeconstruct.com.au>]

On Thu, 2024-06-20 at 16:02 +0200, Zheyu Ma wrote:
> ASan detected a global-buffer-overflow error in the aspeed_gpio_read()
> function. This issue occurred when reading beyond the bounds of the
> reg_table.
> 
> To enhance the safety and maintainability of the Aspeed GPIO code, this commit
> introduces a reg_table_count member to the AspeedGPIOClass structure. This
> change ensures that the size of the GPIO register table is explicitly tracked
> and initialized, reducing the risk of errors if new register tables are
> introduced in the future.
> 
> Reproducer:
> cat << EOF | qemu-system-aarch64 -display none \
> -machine accel=qtest, -m 512M -machine ast1030-evb -qtest stdio
> readq 0x7e780272
> EOF
> 
> ASAN log indicating the issue:
> ==2602930==ERROR: AddressSanitizer: global-buffer-overflow on address 0x55a5da29e128 at pc 0x55a5d700dc62 bp 0x7fff096c4e90 sp 0x7fff096c4e88
> READ of size 2 at 0x55a5da29e128 thread T0
>     #0 0x55a5d700dc61 in aspeed_gpio_read hw/gpio/aspeed_gpio.c:564:14
>     #1 0x55a5d933f3ab in memory_region_read_accessor system/memory.c:445:11
>     #2 0x55a5d92fba40 in access_with_adjusted_size system/memory.c:573:18
>     #3 0x55a5d92f842c in memory_region_dispatch_read1 system/memory.c:1426:16
>     #4 0x55a5d92f7b68 in memory_region_dispatch_read system/memory.c:1459:9
>     #5 0x55a5d9376ad1 in flatview_read_continue_step system/physmem.c:2836:18
>     #6 0x55a5d9376399 in flatview_read_continue system/physmem.c:2877:19
>     #7 0x55a5d93775b8 in flatview_read system/physmem.c:2907:12
> 
> Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>

Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au>