diff options
| author | Stefan Haberland <sth@linux.ibm.com> | 2018-11-21 12:39:47 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2019-01-28 15:43:17 +0100 |
| commit | 4a8ef6999bce998fa5813023a9a6b56eea329dba (patch) | |
| tree | f0fb49dc57dbe05309debcf6586e19bdba99f21d | |
| parent | 634692ab7007e8e3fec758ab0b26e65abf7c79e0 (diff) | |
s390/dasd: fix using offset into zero size array error
Dan Carpenter reported the following:
The patch 52898025cf7d: "[S390] dasd: security and PSF update patch
for EMC CKD ioctl" from Mar 8, 2010, leads to the following static
checker warning:
drivers/s390/block/dasd_eckd.c:4486 dasd_symm_io()
error: using offset into zero size array 'psf_data[]'
drivers/s390/block/dasd_eckd.c
4458 /* Copy parms from caller */
4459 rc = -EFAULT;
4460 if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
^^^^^^^
The user can specify any "usrparm.psf_data_len". They choose zero by
mistake.
4461 goto out;
4462 if (is_compat_task()) {
4463 /* Make sure pointers are sane even on 31 bit. */
4464 rc = -EINVAL;
4465 if ((usrparm.psf_data >> 32) != 0)
4466 goto out;
4467 if ((usrparm.rssd_result >> 32) != 0)
4468 goto out;
4469 usrparm.psf_data &= 0x7fffffffULL;
4470 usrparm.rssd_result &= 0x7fffffffULL;
4471 }
4472 /* alloc I/O data area */
4473 psf_data = kzalloc(usrparm.psf_data_len, GFP_KERNEL
| GFP_DMA);
4474 rssd_result = kzalloc(usrparm.rssd_result_len, GFP_KERNEL
| GFP_DMA);
4475 if (!psf_data || !rssd_result) {
kzalloc() returns a ZERO_SIZE_PTR (0x16).
4476 rc = -ENOMEM;
4477 goto out_free;
4478 }
4479
4480 /* get syscall header from user space */
4481 rc = -EFAULT;
4482 if (copy_from_user(psf_data,
4483 (void __user *)(unsigned long)
usrparm.psf_data,
4484 usrparm.psf_data_len))
That all works great.
4485 goto out_free;
4486 psf0 = psf_data[0];
4487 psf1 = psf_data[1];
But now we're assuming that "->psf_data_len" was at least 2 bytes.
Fix this by checking the user specified length psf_data_len.
Fixes: 52898025cf7d ("[S390] dasd: security and PSF update patch for EMC CKD ioctl")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
| -rw-r--r-- | drivers/s390/block/dasd_eckd.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index 4e7b55a14b1a..6e294b4d3635 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -4469,6 +4469,14 @@ static int dasd_symm_io(struct dasd_device *device, void __user *argp) usrparm.psf_data &= 0x7fffffffULL; usrparm.rssd_result &= 0x7fffffffULL; } + /* at least 2 bytes are accessed and should be allocated */ + if (usrparm.psf_data_len < 2) { + DBF_DEV_EVENT(DBF_WARNING, device, + "Symmetrix ioctl invalid data length %d", + usrparm.psf_data_len); + rc = -EINVAL; + goto out; + } /* alloc I/O data area */ psf_data = kzalloc(usrparm.psf_data_len, GFP_KERNEL | GFP_DMA); rssd_result = kzalloc(usrparm.rssd_result_len, GFP_KERNEL | GFP_DMA); |