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Re: [Qemu-devel] [PATCH v2] scsi: check page count while initialising de
From: |
P J P |
Subject: |
Re: [Qemu-devel] [PATCH v2] scsi: check page count while initialising descriptor rings |
Date: |
Thu, 1 Sep 2016 10:20:20 +0530 (IST) |
Hello Dmitry,
+-- On Wed, 31 Aug 2016, Dmitry Fleytman wrote --+
| > - if ((ri->reqRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)
| > - || (ri->cmpRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)) {
| > - return -1;
| > - }
|
| Hello Prasad,
|
| Why did you decide to move this logic out of pvscsi_ring_init_data()?
| Why not just amend existing “if" as you did in v1 of this patch?
'ri->reqRingNumPages' and 'ri->cmpRingNumPages' values are also used in
routine 'pvscsi_dbg_dump_tx_rings_config' before 'pvscsi_ring_init_data' call.
if they were to have arbitrary values, this loop could run longer leading to
OOB memory access.
for (i = 0; i < rc->reqRingNumPages; i++) {
trace_pvscsi_tx_rings_ppn("Request Ring", rc->reqRingPPNs[i]);
}
Moving above logic to 'pvscsi_on_cmd_setup_rings' helps both functions.
Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F
- Re: [Qemu-devel] [PATCH v2] scsi: check page count while initialising descriptor rings,
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