| From 7bbb186ab1461080fbb4559acbe3ec19fd7b745c Mon Sep 17 00:00:00 2001 |
| From: Gen Zhang <blackgod016574@gmail.com> |
| Date: Thu, 30 May 2019 09:10:30 +0800 |
| Subject: [PATCH] scsi: mpt3sas_ctl: fix double-fetch bug in _ctl_ioctl_main() |
| |
| commit f9e3ebeea4521652318af903cddeaf033527e93e upstream. |
| |
| In _ctl_ioctl_main(), 'ioctl_header' is fetched the first time from |
| userspace. 'ioctl_header.ioc_number' is then checked. The legal result is |
| saved to 'ioc'. Then, in condition MPT3COMMAND, the whole struct is fetched |
| again from the userspace. Then _ctl_do_mpt_command() is called, 'ioc' and |
| 'karg' as inputs. |
| |
| However, a malicious user can change the 'ioc_number' between the two |
| fetches, which will cause a potential security issues. Moreover, a |
| malicious user can provide a valid 'ioc_number' to pass the check in first |
| fetch, and then modify it in the second fetch. |
| |
| To fix this, we need to recheck the 'ioc_number' in the second fetch. |
| |
| Signed-off-by: Gen Zhang <blackgod016574@gmail.com> |
| Acked-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com> |
| Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c |
| index b2bb47c14d35..5181c03e82a6 100644 |
| --- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c |
| +++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c |
| @@ -2319,6 +2319,10 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg, |
| break; |
| } |
| |
| + if (karg.hdr.ioc_number != ioctl_header.ioc_number) { |
| + ret = -EINVAL; |
| + break; |
| + } |
| if (_IOC_SIZE(cmd) == sizeof(struct mpt3_ioctl_command)) { |
| uarg = arg; |
| ret = _ctl_do_mpt_command(ioc, karg, &uarg->mf); |
| -- |
| 2.7.4 |
| |
