blob: 90437342813b65ebb00af80db76fff4df7f6d1bf [file] [log] [blame]
From 7bbb186ab1461080fbb4559acbe3ec19fd7b745c Mon Sep 17 00:00:00 2001
From: Gen Zhang <>
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 <>
Acked-by: Suganath Prabu S <>
Signed-off-by: Martin K. Petersen <>
Signed-off-by: Paul Gortmaker <>
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,
+ 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);