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[RESEND] libata: if T_LENGTH is zero, dma direction should be DMA_NONE

Message ID 1639408164-4210-1-git-send-email-george.kennedy@oracle.com
State New
Headers show
Series [RESEND] libata: if T_LENGTH is zero, dma direction should be DMA_NONE | expand

Commit Message

George Kennedy Dec. 13, 2021, 3:09 p.m. UTC 
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.

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(+)

Comments

Greg Kroah-Hartman Dec. 13, 2021, 3:19 p.m. UTC | #1 
On Mon, Dec 13, 2021 at 10:09:24AM -0500, 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.
> 
> 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(+)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>
diff mbox series

Patch

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;