Hi Philippe, On Wed, Jun 19, 2024 at 6:29 PM Philippe Mathieu-Daudé <phi...@linaro.org> wrote:
> On 19/6/24 08:49, Zheyu Ma wrote: > > Hi Andrew, > > > > On Wed, Jun 19, 2024 at 1:58 AM Andrew Jeffery > > <and...@codeconstruct.com.au <mailto:and...@codeconstruct.com.au>> > wrote: > > > > Hello Zheyu Ma, > > > > On Tue, 2024-06-18 at 15:09 +0200, Zheyu Ma wrote: > > > Added bounds checking in the aspeed_gpio_read() and > > aspeed_gpio_write() > > > functions to ensure the index idx is within the valid range of the > > > reg_table array. > > > > > > The correct size of reg_table is determined dynamically based on > > whether > > > it is aspeed_3_3v_gpios or aspeed_1_8v_gpios. If idx exceeds the > > > size of reg_table, an error is logged, and the function returns. > > > > > > AddressSanitizer 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 > > > > I'm mildly interested in what you were doing to trigger this. > Certainly > > we could do with a guard in the model to prevent it, but I'm curious > > all the same. > > > > > > Actually, I'm doing the virtual device fuzzing test and trying to > > discover bugs. > > Could you share the reproducer? (As you did in your other patches, > it is very useful to reproduce). > Sure, I've sent a v3 patch. Zheyu > > > > > > > > > Signed-off-by: Zheyu Ma <zheyum...@gmail.com > > <mailto:zheyum...@gmail.com>> > > > --- > > > hw/gpio/aspeed_gpio.c | 26 ++++++++++++++++++++++++++ > > > 1 file changed, 26 insertions(+) > > > > > > diff --git a/hw/gpio/aspeed_gpio.c b/hw/gpio/aspeed_gpio.c > > > index c1781e2ba3..1441046f6c 100644 > > > --- a/hw/gpio/aspeed_gpio.c > > > +++ b/hw/gpio/aspeed_gpio.c > > > @@ -550,6 +550,7 @@ static uint64_t aspeed_gpio_read(void > > *opaque, hwaddr offset, uint32_t size) > > > GPIOSets *set; > > > uint32_t value = 0; > > > uint64_t debounce_value; > > > + uint32_t reg_table_size; > > > > > > idx = offset >> 2; > > > if (idx >= GPIO_DEBOUNCE_TIME_1 && idx <= > > GPIO_DEBOUNCE_TIME_3) { > > > @@ -559,6 +560,18 @@ static uint64_t aspeed_gpio_read(void > > *opaque, hwaddr offset, uint32_t size) > > > return debounce_value; > > > } > > > > > > + if (agc->reg_table == aspeed_3_3v_gpios) { > > > + reg_table_size = GPIO_3_3V_REG_ARRAY_SIZE; > > > + } else { > > > + reg_table_size = GPIO_1_8V_REG_ARRAY_SIZE; > > > + } > > > > I think I'd prefer we add reg_table_size as a member of > AspeedGPIOClass > > and initialise it at the same time as we initialise reg_table. I feel > > it would help maintain safety in the face of future changes (i.e. if > > another reg table were introduced). With that approach the hunk above > > can be dropped. > > > > > + > > > + if (idx >= reg_table_size) { > > > > This condition would then become: > > > > ``` > > if (idx >= agc->reg_table_size) { > > ``` > > > > Thoughts? > > > > > > I agree with you, adding a new member is a more maintainable way, I'll > > send a v2 patch, thanks! > > > > Zheyu > >
