From mboxrd@z Thu Jan 1 00:00:00 1970 From: jmorris@namei.org (James Morris) Date: Mon, 19 Mar 2018 15:52:18 +1100 (AEDT) Subject: [PATCH v2] exec: Set file unwritable before LSM check In-Reply-To: <20180309193020.GA5149@beast> References: <20180309193020.GA5149@beast> Message-ID: To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org On Fri, 9 Mar 2018, Kees Cook wrote: > The LSM check should happen after the file has been confirmed to be > unchanging. Without this, we could have a race between the Time of Check > (the call to security_kernel_read_file() which could read the file and > make access policy decisions) and the Time of Use (starting with > kernel_read_file()'s reading of the file contents). In theory, file > contents could change between the two. > > Signed-off-by: Kees Cook > --- > v2: Clarify the ToC/ToU race (Linus) Applied to git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git next-general and next-testing -- James Morris -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html