From: Borys <borysp@invisiblethingslab.com>
To: jarkko@kernel.org, dave.hansen@linux.intel.com,
linux-sgx@vger.kernel.org
Cc: mkow@invisiblethingslab.com
Subject: sgx_validate_offset_length bug
Date: Mon, 3 Oct 2022 19:19:21 +0200 [thread overview]
Message-ID: <9e1e61cf-39d9-8039-b2e4-f0a3804fe493@invisiblethingslab.com> (raw)
Hi,
I've stumbled upon "sgx_validate_offset_length" function in "arch/x86/kernel/cpu/sgx/ioctl.c" (all of this is based on 6.0-rc7 version), which does not entirely do what it claims. "offset" and "length" parameters are provided by userspace and as such their addition can overflow, which may result in this function approving malicious values. Fortunately this does not result in any exploitable bugs at the moment (or at least I couldn't find any), but this might change if "sgx_validate_offset_length" is used in a new context or current usages are changed, so it might be worth fixing anyway. Simple overflow check `offset + length < offset` should be enough.
Best regards,
Borys
next reply other threads:[~2022-10-03 17:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-03 17:19 Borys [this message]
2022-10-03 17:33 ` sgx_validate_offset_length bug Reinette Chatre
2022-10-03 17:58 ` Reinette Chatre
2022-10-04 13:22 ` Borys
2022-10-04 15:21 ` Reinette Chatre
2022-10-04 21:50 ` Jarkko Sakkinen
2022-10-04 23:02 ` Borys
2022-10-04 23:13 ` Jarkko Sakkinen
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