Messages in this thread | | | Date | Tue, 14 Dec 2021 08:50:44 +0900 | Subject | Re: [PATCH RESEND 2] libata: if T_LENGTH is zero, dma direction should be DMA_NONE | From | Damien Le Moal <> |
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On 2021/12/14 7:15, George Kennedy wrote: > > > On 12/13/2021 4:37 PM, Damien Le Moal wrote: >> On 2021/12/14 0:33, George Kennedy wrote: >>> Avoid data corruption by rejecting pass-through commands where >>> T_LENGTH is zero (No data is transferred) and the dma direction >>> is not DMA_NONE. >>> >>> Cc:<stable@vger.kernel.org> # 5.4.y >> 5.4 only ? What about other LTS versions ? They do not have that bug ? > Our distros are based on 5.4.y, 5.15.y and 4.14.y, so the fix should go > there, > but it looks like the fix is also needed in: 5.14.y, 5.13.y, 5.10.y, and > 4.19.y.
Then please resend with:
Cc: stable@vger.kernel.org
No version specified.
> > Thank you, > George >> >>> Reported-by: syzkaller<syzkaller@googlegroups.com> >>> Signed-off-by: George Kennedy<george.kennedy@oracle.com> >>> --- >>> drivers/ata/libata-scsi.c | 6 ++++++ >>> 1 file changed, 6 insertions(+) >>> >>> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c >>> index 1b84d55..d428392 100644 >>> --- a/drivers/ata/libata-scsi.c >>> +++ b/drivers/ata/libata-scsi.c >>> @@ -2859,6 +2859,12 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc) >>> goto invalid_fld; >>> } >>> >>> + /* if T_LENGTH is zero (No data is transferred), then dir should be DMA_NONE */ >>> + if ((cdb[2 + cdb_offset] & 3) == 0 && scmd->sc_data_direction != DMA_NONE) { >>> + fp = 2 + cdb_offset; >>> + goto invalid_fld; >>> + } >>> + >>> if (ata_is_ncq(tf->protocol) && (cdb[2 + cdb_offset] & 0x3) == 0)
cdb[2 + cdb_offset] & 3) is used again for the ncq test, so you can group things:
if (!(cdb[2 + cdb_offset] & 0x3)) { /* * When T_LENGTH is zero (no data is transferred), * then dir should be DMA_NONE. */ if (scmd->sc_data_direction != DMA_NONE) { fp = 2 + cdb_offset; goto invalid_fld; }
if (ata_is_ncq(tf->protocol)) tf->protocol = ATA_PROT_NCQ_NODATA; }
>>> tf->protocol = ATA_PROT_NCQ_NODATA; >>> >>> -- 1.8.3.1 >>> >> >
-- Damien Le Moal Western Digital Research
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