On 4/11/24 19:30, Mikhail Ukhin wrote:
> No upstream commit exists for this patch.
>
> 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") upstream.
> 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>
> Signed-off-by: Mikhail Ukhin <mish.uxin2012@xxxxxxxxx>
> ---
> v2: The new addresses were added and the text was updated.
> 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;
This check should really be in ata_scsi_var_len_cdb_xlat(). Please move it to
that function.
>
> if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
> if (unlikely(scmd->cmd_len > dev->cdb_len))
--
Damien Le Moal
Western Digital Research
