From 78f27c43eb166c931b0919fa7784734573d3f502 Mon Sep 17 00:00:00 2001 From: George Kennedy Date: Tue, 14 Dec 2021 09:45:10 -0500 Subject: [PATCH] libata: if T_LENGTH is zero, dma direction should be DMA_NONE commit 5da5231bb47864e5dd6c6731151e98b6ee498827 upstream. 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: Reported-by: syzkaller Signed-off-by: George Kennedy Signed-off-by: Damien Le Moal Signed-off-by: Greg Kroah-Hartman --- drivers/ata/libata-scsi.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 1fb4611..1030361 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -2826,8 +2826,19 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc) goto invalid_fld; } - if (ata_is_ncq(tf->protocol) && (cdb[2 + cdb_offset] & 0x3) == 0) - tf->protocol = ATA_PROT_NCQ_NODATA; + if ((cdb[2 + cdb_offset] & 0x3) == 0) { + /* + * When T_LENGTH is zero (No data is transferred), 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; + } /* enable LBA */ tf->flags |= ATA_TFLAG_LBA; -- 2.7.4