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Re: [PATCH] pci: check bus pointer before dereference
From: |
Li Qiang |
Subject: |
Re: [PATCH] pci: check bus pointer before dereference |
Date: |
Tue, 15 Sep 2020 21:51:58 +0800 |
P J P <ppandit@redhat.com> 于2020年8月27日周四 下午7:52写道:
>
> From: Prasad J Pandit <pjp@fedoraproject.org>
>
> While mapping IRQ level in pci_change_irq_level() routine,
> it does not check if pci_get_bus() returned a valid pointer.
> It may lead to a NULL pointer dereference issue. Add check to
> avoid it.
>
> -> https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Flsi_nullptr1
> ==1183858==Hint: address points to the zero page.
> #0 pci_change_irq_level hw/pci/pci.c:259
> #1 pci_irq_handler hw/pci/pci.c:1445
> #2 pci_set_irq hw/pci/pci.c:1463
> #3 lsi_set_irq hw/scsi/lsi53c895a.c:488
> #4 lsi_update_irq hw/scsi/lsi53c895a.c:523
> #5 lsi_script_scsi_interrupt hw/scsi/lsi53c895a.c:554
> #6 lsi_execute_script hw/scsi/lsi53c895a.c:1149
> #7 lsi_reg_writeb hw/scsi/lsi53c895a.c:1984
> #8 lsi_io_write hw/scsi/lsi53c895a.c:2146
> ...
>
> Reported-by: Ruhr-University <bugs-syssec@rub.de>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
> hw/pci/pci.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index de0fae10ab..df5a2c3294 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -253,6 +253,9 @@ static void pci_change_irq_level(PCIDevice *pci_dev, int
> irq_num, int change)
> PCIBus *bus;
> for (;;) {
> bus = pci_get_bus(pci_dev);
> + if (!bus) {
Hi Prasad,
I think in normal this 'bus' will be not NULL.
I have look at the link in the commit msg.
I find it is another DMA to MMIO issue which we have discussed a lot
but didn't come up with an
satisfying solution.
Maybe we can try to the DMA to MMIO issue direction.
CC: Peter, Jason and Alex
Thanks,
Li Qiang
> + return;
> + }
> irq_num = bus->map_irq(pci_dev, irq_num);
> if (bus->set_irq)
> break;
> --
> 2.26.2
>
>
- Re: [PATCH] pci: check bus pointer before dereference, P J P, 2020/09/15
- Re: [PATCH] pci: check bus pointer before dereference,
Li Qiang <=
- Re: [PATCH] pci: check bus pointer before dereference, Philippe Mathieu-Daudé, 2020/09/15
- Re: [PATCH] pci: check bus pointer before dereference, P J P, 2020/09/16
- Re: [PATCH] pci: check bus pointer before dereference, Peter Maydell, 2020/09/16
- Re: [PATCH] pci: check bus pointer before dereference, P J P, 2020/09/28
- Re: [PATCH] pci: check bus pointer before dereference, P J P, 2020/09/30
- Re: [PATCH] pci: check bus pointer before dereference, Igor Mammedov, 2020/09/30
- Re: [PATCH] pci: check bus pointer before dereference, P J P, 2020/09/30