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 ce70fd9a551af7424a7dace2a1ba05a7de8eae27. 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@gmail.com Signed-off-by: Mikhail Ivanov iwanov-23@bk.ru --- 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))