On Thu, 2009-07-30 at 14:31 -0400, Eric Paris wrote: > On Thu, 2009-07-30 at 13:50 -0400, Eric Paris wrote: > > On Thu, 2009-07-30 at 11:58 -0400, Stephen Smalley wrote: > > > On Thu, 2009-07-30 at 10:54 -0500, Serge E. Hallyn wrote: > > > > Quoting Eric Paris (eparis@xxxxxxxxxx): > > > > > On Thu, 2009-07-30 at 00:14 -0500, Serge E. Hallyn wrote: > > > > > > Quoting Eric Paris (eparis@xxxxxxxxxx): > > > > > > > Currently we duplicate the mmap_min_addr test in cap_file_mmap and in > > > > > > > security_file_mmap if !CONFIG_SECURITY. This patch moves cap_file_mmap > > > > > > > into commoncap.c and then calls that function directly from > > > > > > > security_file_mmap ifndef CONFIG_SECURITY like all of the other capability > > > > > > > checks are done. > > > > > > > > > > > > It also > > > > > > > > > > > > 1. changes the return value in error case from -EACCES to > > > > > > -EPERM > > > > > > 2. no onger sets PF_SUPERPRIV in t->flags if the capability > > > > > > is used. > > > > > > > > > > > > Do we care about these? > > > > > > > > > > Personally, not really, but I'll gladly put them back if you care. #2 > > > > > seems more interesting to me than number 1. I actually kinda like > > > > > getting EPERM from caps rather than EACCES since them I know if I was > > > > > denied by selinux or by caps..... > > > > > > > > > > -Eric > > > > > > > > Yup, I asked bc I didn't particularly care myself. > > > > > > > > I think I agree with you about -EPERM being better anyway. However I > > > > (now) think in this case PF_SUPERPRIV definately should be set, as this > > > > is a clear use of a capability to do something that couldn't have been > > > > done without it. > > > > > > On a related but different note, we should consider all current uses of > > > cap_capable(), as they represent capability checks that will not be > > > subject to a further restrictive check by other security modules. In > > > this case and in the vm_enough_memory case, that is intentional, but not > > > so clear for other uses in commoncap.c. > > > > Most of commoncap.c is called either as a secondary hook from the active > > lsm (aka selinux calls the commoncap.c functions) or in the ! > > CONFIG_SECURITY case. > > > > I'll audit this afternoon to see which of them might not fit these > > rules.... > > I just went through all of the cap_* function in commoncap.c to see > which of them are being or are not being called from the selinux hooks. > Only 3 of them look interesting. > > cap_inode_setxattr > cap_inode_removexattr > cap_vm_enough_memory > > All of the other functions are either called from hooks.c or SELinux > does not define that LSM hook, so it just defaults to the cap_* hook. > > These 3 are all a bit odd because the logic inside the cap_ hook is > duplicated inside the selinux_ hook. I'd much rather see the selinux_ > hook call the cap_ hook. I'm going to think on that topic, but it's a > different set of patches and I don't see missing checks today as the > logic seems to line up. Yes, those 3 aren't a problem. I suppose selinux_inode_setotherxattr() could be changed to call cap_inode_setxattr() before the SELinux setattr check, as that would only happen in the non-selinux attribute case. -- Stephen Smalley National Security Agency -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@xxxxxxxxxxxxx with the words "unsubscribe selinux" without quotes as the message.
