Messages in this thread | | | Date | Wed, 28 Jul 2021 12:35:07 +0200 | Subject | Re: [PATCH] iommu: check if group is NULL before remove device | From | Frank Wunderlich <> |
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Hi Joerg,
Sorry for late reply, somehow i marked message as read without answering it.
Am 15. Juli 2021 09:20:04 MESZ schrieb Joerg Roedel <joro@8bytes.org>: >On Thu, Jul 15, 2021 at 09:11:50AM +0200, Frank Wunderlich wrote: >> From: Frank Wunderlich <frank-w@public-files.de> >> >> if probe is failing, iommu_group may be not initialized, > >Sentences start with capital letters. > >IOMMU patch subjects too, after the 'iommu:' prefix.
Will fix these in v2
>> so freeing it will result in NULL pointer access > >Please describe in more detail how this NULL-ptr dereference is >triggered.
I had this by testing this series: https://patchwork.kernel.org/project/linux-mediatek/list/?series=515129
Initialization in mtk driver was failed (i guess the iommu group was not yet created), cleanup was started and so this function is called with a NULL group pointer. I can try to find my debug-trace if you need a kind of backtrace.
regards Frank
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