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| author | Stefan Haberland <sth@linux.ibm.com> | 2018-11-21 14:39:47 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-23 15:19:41 +0300 |
| commit | 6a5cda42ae220d81b8403d413db5337a0a07534a (patch) | |
| tree | ea054682667f4723fe1882f1a20c8e2eaeea9cf5 /drivers/s390 | |
| parent | 06d73d17b05ba2942ebdfc99fb660df5c7cbba69 (diff) | |
| download | linux-6a5cda42ae220d81b8403d413db5337a0a07534a.tar.xz | |
s390/dasd: fix using offset into zero size array error
[ Upstream commit 4a8ef6999bce998fa5813023a9a6b56eea329dba ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/s390')
| -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 be17de9807b6..11c6335b1951 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -4508,6 +4508,14 @@ 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); |