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authorStefan Haberland2018-11-21 12:39:47 +0100
committerMartin Schwidefsky2019-01-28 15:43:17 +0100
commit4a8ef6999bce998fa5813023a9a6b56eea329dba (patch)
treef0fb49dc57dbe05309debcf6586e19bdba99f21d /drivers/s390
parent634692ab7007e8e3fec758ab0b26e65abf7c79e0 (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>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/block/dasd_eckd.c8
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);