Commit f9e3ebee authored by Gen Zhang's avatar Gen Zhang Committed by Martin K. Petersen

scsi: mpt3sas_ctl: fix double-fetch bug in _ctl_ioctl_main()

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: default avatarGen Zhang <blackgod016574@gmail.com>
Acked-by: default avatarSuganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 82174440
...@@ -2319,6 +2319,10 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg, ...@@ -2319,6 +2319,10 @@ _ctl_ioctl_main(struct file *file, unsigned int cmd, void __user *arg,
break; break;
} }
if (karg.hdr.ioc_number != ioctl_header.ioc_number) {
ret = -EINVAL;
break;
}
if (_IOC_SIZE(cmd) == sizeof(struct mpt3_ioctl_command)) { if (_IOC_SIZE(cmd) == sizeof(struct mpt3_ioctl_command)) {
uarg = arg; uarg = arg;
ret = _ctl_do_mpt_command(ioc, karg, &uarg->mf); ret = _ctl_do_mpt_command(ioc, karg, &uarg->mf);
......
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