[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v2] hw/ide: check null block before _cancel_dma_sync
From: |
P J P |
Subject: |
Re: [PATCH v2] hw/ide: check null block before _cancel_dma_sync |
Date: |
Fri, 18 Sep 2020 15:55:52 +0530 (IST) |
+-- On Fri, 18 Sep 2020, Li Qiang wrote --+
| Update v2: use an assert() call
| ->https://lists.nongnu.org/archive/html/qemu-devel/2020-08/msg08336.html
...
| I think it is better to defer this check to 'ide_cancel_dma_sync'.
| 'ide_cancel_dma_sync' is also called by 'cmd_device_reset' and all of the
| handlers of 'ide_cmd_table' will check whether the 's->blk' is NULL in the
| beginning of 'ide_exec_cmd'.
|
| So I think it is reasonable to check 's->blk' at the begining of
| 'ide_cancel_dma_sync'.
* Yes, earlier patch v1 above does the same.
* From Peter's reply in another thread of similar issue I gather, issue is
setting 'blk' to NULL, even erroneously. So (blk == NULL) check should be
done where 'blk' is set to null, rather than where it is dereferenced.
* At the dereference point, assert(3) is good.
Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
8685 545E B54C 486B C6EB 271E E285 8B5A F050 DE8D