Fuzzing of 5.10 stable branch reports a slab-out-of-bounds error in
ata_scsi_pass_thru.
The error is fixed in 5.18 by commit ce70fd9a551a ("scsi: core: Remove the
cmd field from struct scsi_request").
Backporting this commit would require significant changes to the code so
it is bettter to use a simple fix for that particular error.
The problem is that the length of the received SCSI command is not
validated if scsi_op == VARIABLE_LENGTH_CMD. It can lead to out-of-bounds
reading if the user sends a request with SCSI command of length less than
32.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Signed-off-by: Artem Sadovnikov <ancowi69@xxxxxxxxx>
Signed-off-by: Mikhail Ivanov <iwanov-23@xxxxx>
---
drivers/ata/libata-scsi.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index dfa090ccd21c..77589e911d3d 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -4065,6 +4065,9 @@ int __ata_scsi_queuecmd(struct scsi_cmnd *scmd, struct ata_device *dev)
if (unlikely(!scmd->cmd_len))
goto bad_cdb_len;
+
+ if (scsi_op == VARIABLE_LENGTH_CMD && scmd->cmd_len < 32)
+ goto bad_cdb_len;
if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
if (unlikely(scmd->cmd_len > dev->cdb_len))
--
2.25.1
