From mboxrd@z Thu Jan 1 00:00:00 1970 From: zohar@linux.vnet.ibm.com (Mimi Zohar) Date: Tue, 28 Nov 2017 17:33:10 -0500 Subject: [PATCH V3 2/2] IMA: Support using new creds in appraisal policy In-Reply-To: References: <20171026084055.25482-1-mjg59@google.com> <20171026084055.25482-2-mjg59@google.com> <1511902135.3473.5.camel@linux.vnet.ibm.com> <1511904917.3473.15.camel@linux.vnet.ibm.com> Message-ID: <1511908390.3473.30.camel@linux.vnet.ibm.com> To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org On Tue, 2017-11-28 at 13:37 -0800, Matthew Garrett wrote: > On Tue, Nov 28, 2017 at 1:35 PM, Mimi Zohar wrote: > > On Tue, 2017-11-28 at 13:22 -0800, Matthew Garrett wrote: > >> We need to check against the appropriate credentials structure, and > >> since we're doing this before commit_creds() has been called we can't > >> just do it against the one in the task structure. For BPRM_CHECK > >> that'll be current_cred(), which means there's no change in > >> functionality, whereas for CREDS_CHECK it'll be the new credentials > >> structure. > > > > The existing code calls security_task_getsecid() with "current" not > > "current_cred". Will replacing security_task_getsecid() with > > security_cred_getsecid() return the same info for the original > > BRPM_CHECK? > > security_task_getsecid(current) will give the same results as > security_cred_getsecid(current_creds()) Unwinding security_task_getsecid(current) looks like it is using real_cred, while current_cred() is using cred. selinux_task_getsecid() -> task_sid() -> cred_sid(__task_cred()) #define __task_cred(task) \ rcu_dereference((task)->real_cred) selinux_task_getsecid() -> cred_sid() #define current_cred() \ rcu_dereference_protected(current->cred, 1) Is the change intentional? Mimi -- 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