From 281cac74a213639fa7a4d1b60553d011a4a11d6f Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 5 Dec 2014 17:19:27 -0600 Subject: groups: Consolidate the setgroups permission checks commit 7ff4d90b4c24a03666f296c3d4878cd39001e81e upstream. Today there are 3 instances of setgroups and due to an oversight their permission checking has diverged. Add a common function so that they may all share the same permission checking code. This corrects the current oversight in the current permission checks and adds a helper to avoid this in the future. A user namespace security fix will update this new helper, shortly. Signed-off-by: "Eric W. Biederman" Signed-off-by: Jiri Slaby --- kernel/groups.c | 9 ++++++++- kernel/uid16.c | 2 +- 2 files changed, 9 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/groups.c b/kernel/groups.c index 90cf1c38c8ea..984bb629c68c 100644 --- a/kernel/groups.c +++ b/kernel/groups.c @@ -223,6 +223,13 @@ out: return i; } +bool may_setgroups(void) +{ + struct user_namespace *user_ns = current_user_ns(); + + return ns_capable(user_ns, CAP_SETGID); +} + /* * SMP: Our groups are copy-on-write. We can set them safely * without another task interfering. @@ -233,7 +240,7 @@ SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist) struct group_info *group_info; int retval; - if (!ns_capable(current_user_ns(), CAP_SETGID)) + if (!may_setgroups()) return -EPERM; if ((unsigned)gidsetsize > NGROUPS_MAX) return -EINVAL; diff --git a/kernel/uid16.c b/kernel/uid16.c index 602e5bbbceff..d58cc4d8f0d1 100644 --- a/kernel/uid16.c +++ b/kernel/uid16.c @@ -176,7 +176,7 @@ SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist) struct group_info *group_info; int retval; - if (!ns_capable(current_user_ns(), CAP_SETGID)) + if (!may_setgroups()) return -EPERM; if ((unsigned)gidsetsize > NGROUPS_MAX) return -EINVAL; -- cgit v1.2.3