Re: [PATCH RESEND 2] libata: if T_LENGTH is zero, dma direction should be DMA_NONE
From: Damien Le Moal <hidden>
Date: 2021-12-13 21:37:34
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lkml
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:[off-list ref] # 5.4.y
5.4 only ? What about other LTS versions ? They do not have that bug ?
quoted hunk ↗ jump to hunk
Reported-by: syzkaller<redacted> Signed-off-by: George Kennedy<redacted> --- 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) tf->protocol = ATA_PROT_NCQ_NODATA; -- 1.8.3.1
-- Damien Le Moal Western Digital Research