| Message ID | 20240328150026.9129-1-mish.uxin2012@yandex.ru |
|---|---|
| State | New |
| Headers | show |
| Series | [5.10/5.15] ata: libata-scsi: check cdb length for VARIABLE_LENGTH_CMD commands | expand |
On 3/29/24 00:00, Mikhail Ukhin wrote: > 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@gmail.com> > Signed-off-by: Mikhail Ivanov <iwanov-23@bk.ru> This looks OK to me, but: 1) Please stop using the wrong email address for me. Use scripts/get_maintainer.pl to see the correct email address (the one I am using now). And maintainers & main list should not be on cc but part of the "to:" addressing. 2) Please read Documentation/process/stable-kernel-rules.rst and see Option 3. I cannot take this patch. It needs to go through the stable tree after I Ack it. > --- > 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))
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))
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@gmail.com> Signed-off-by: Mikhail Ivanov <iwanov-23@bk.ru> --- drivers/ata/libata-scsi.c | 3 +++ 1 file changed, 3 insertions(+)