linux/security/commoncap.c, branch v3.5

split ->file_mmap() into ->mmap_addr()/->mmap_file()

2012-05-31T17:11:54Z

... i.e. file-dependent and address-dependent checks. Signed-off-by: Al Viro

split cap_mmap_addr() out of cap_file_mmap()

2012-05-31T17:10:54Z

... switch callers. Signed-off-by: Al Viro

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2012-05-24T00:42:39Z

Pull user namespace enhancements from Eric Biederman: "This is a course correction for the user namespace, so that we can reach an inexpensive, maintainable, and reasonably complete implementation. Highlights: - Config guards make it impossible to enable the user namespace and code that has not been converted to be user namespace safe. - Use of the new kuid_t type ensures the if you somehow get past the config guards the kernel will encounter type errors if you enable user namespaces and attempt to compile in code whose permission checks have not been updated to be user namespace safe. - All uids from child user namespaces are mapped into the initial user namespace before they are processed. Removing the need to add an additional check to see if the user namespace of the compared uids remains the same. - With the user namespaces compiled out the performance is as good or better than it is today. - For most operations absolutely nothing changes performance or operationally with the user namespace enabled. - The worst case performance I could come up with was timing 1 billion cache cold stat operations with the user namespace code enabled. This went from 156s to 164s on my laptop (or 156ns to 164ns per stat operation). - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value. Most uid/gid setting system calls treat these value specially anyway so attempting to use -1 as a uid would likely cause entertaining failures in userspace. - If setuid is called with a uid that can not be mapped setuid fails. I have looked at sendmail, login, ssh and every other program I could think of that would call setuid and they all check for and handle the case where setuid fails. - If stat or a similar system call is called from a context in which we can not map a uid we lie and return overflowuid. The LFS experience suggests not lying and returning an error code might be better, but the historical precedent with uids is different and I can not think of anything that would break by lying about a uid we can't map. - Capabilities are localized to the current user namespace making it safe to give the initial user in a user namespace all capabilities. My git tree covers all of the modifications needed to convert the core kernel and enough changes to make a system bootable to runlevel 1." Fix up trivial conflicts due to nearby independent changes in fs/stat.c * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits) userns: Silence silly gcc warning. cred: use correct cred accessor with regards to rcu read lock userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq userns: Convert cgroup permission checks to use uid_eq userns: Convert tmpfs to use kuid and kgid where appropriate userns: Convert sysfs to use kgid/kuid where appropriate userns: Convert sysctl permission checks to use kuid and kgids. userns: Convert proc to use kuid/kgid where appropriate userns: Convert ext4 to user kuid/kgid where appropriate userns: Convert ext3 to use kuid/kgid where appropriate userns: Convert ext2 to use kuid/kgid where appropriate. userns: Convert devpts to use kuid/kgid where appropriate userns: Convert binary formats to use kuid/kgid where appropriate userns: Add negative depends on entries to avoid building code that is userns unsafe userns: signal remove unnecessary map_cred_ns userns: Teach inode_capable to understand inodes whose uids map to other namespaces. userns: Fail exec for suid and sgid binaries with ids outside our user namespace. userns: Convert stat to return values mapped from kuids and kgids userns: Convert user specfied uids and gids in chown into kuids and kgid userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs ...

Merge tag 'v3.4-rc5' into next

2012-05-04T02:46:40Z

Linux 3.4-rc5 Merge to pull in prerequisite change for Smack: 86812bb0de1a3758dc6c7aa01a763158a7c0638a Requested by Casey.

userns: Convert capabilities related permsion checks

2012-05-03T10:28:40Z

- Use uid_eq when comparing kuids Use gid_eq when comparing kgids - Use make_kuid(user_ns, 0) to talk about the user_namespace root uid Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman

userns: Store uid and gid values in struct cred with kuid_t and kgid_t types

2012-05-03T10:28:38Z

cred.h and a few trivial users of struct cred are changed. The rest of the users of struct cred are left for other patches as there are too many changes to make in one go and leave the change reviewable. If the user namespace is disabled and CONFIG_UIDGID_STRICT_TYPE_CHECKS are disabled the code will contiue to compile and behave correctly. Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman

userns: Simplify the user_namespace by making userns->creator a kuid.

2012-04-26T09:00:59Z

- Transform userns->creator from a user_struct reference to a simple kuid_t, kgid_t pair. In cap_capable this allows the check to see if we are the creator of a namespace to become the classic suser style euid permission check. This allows us to remove the need for a struct cred in the mapping functions and still be able to dispaly the user namespace creators uid and gid as 0. - Remove the now unnecessary delayed_work in free_user_ns. All that is left for free_user_ns to do is to call kmem_cache_free and put_user_ns. Those functions can be called in any context so call them directly from free_user_ns removing the need for delayed work. Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman

security: fix compile error in commoncap.c

2012-04-19T02:56:39Z

Add missing "personality.h" security/commoncap.c: In function 'cap_bprm_set_creds': security/commoncap.c:510: error: 'PER_CLEAR_ON_SETID' undeclared (first use in this function) security/commoncap.c:510: error: (Each undeclared identifier is reported only once security/commoncap.c:510: error: for each function it appears in.) Signed-off-by: Jonghwan Choi Acked-by: Serge Hallyn Signed-off-by: James Morris

fcaps: clear the same personality flags as suid when fcaps are used

2012-04-18T02:37:56Z

If a process increases permissions using fcaps all of the dangerous personality flags which are cleared for suid apps should also be cleared. Thus programs given priviledge with fcaps will continue to have address space randomization enabled even if the parent tried to disable it to make it easier to attack. Signed-off-by: Eric Paris Reviewed-by: Serge Hallyn Signed-off-by: James Morris

Add PR_{GET,SET}_NO_NEW_PRIVS to prevent execve from granting privs

2012-04-14T01:13:18Z

With this change, calling prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) disables privilege granting operations at execve-time. For example, a process will not be able to execute a setuid binary to change their uid or gid if this bit is set. The same is true for file capabilities. Additionally, LSM_UNSAFE_NO_NEW_PRIVS is defined to ensure that LSMs respect the requested behavior. To determine if the NO_NEW_PRIVS bit is set, a task may call prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); It returns 1 if set and 0 if it is not set. If any of the arguments are non-zero, it will return -1 and set errno to -EINVAL. (PR_SET_NO_NEW_PRIVS behaves similarly.) This functionality is desired for the proposed seccomp filter patch series. By using PR_SET_NO_NEW_PRIVS, it allows a task to modify the system call behavior for itself and its child tasks without being able to impact the behavior of a more privileged task. Another potential use is making certain privileged operations unprivileged. For example, chroot may be considered "safe" if it cannot affect privileged tasks. Note, this patch causes execve to fail when PR_SET_NO_NEW_PRIVS is set and AppArmor is in use. It is fixed in a subsequent patch. Signed-off-by: Andy Lutomirski Signed-off-by: Will Drewry Acked-by: Eric Paris Acked-by: Kees Cook v18: updated change desc v17: using new define values as per 3.4 Signed-off-by: James Morris