userns: Convert group_info values from gid_t to kgid_t.

As a first step to converting struct cred to be all kuid_t and kgid_t
values convert the group values stored in group_info to always be
kgid_t values.   Unless user namespaces are used this change should
have no effect.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

12 files changed, 104 insertions, 49 deletions

diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index ab64bdbab2ae..f0273ed760ef 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -173,11 +173,14 @@ asmlinkage long sys32_setfsgid16(u16 gid)
 
 static int groups16_to_user(u16 __user *grouplist, struct group_info *group_info)
 {
+        struct user_namespace *user_ns = current_user_ns();
         int i;
         u16 group;
+        kgid_t kgid;
 
         for (i = 0; i < group_info->ngroups; i++) {
-                group = (u16)GROUP_AT(group_info, i);
+                kgid = GROUP_AT(group_info, i);
+                group = (u16)from_kgid_munged(user_ns, kgid);
                 if (put_user(group, grouplist+i))
                         return -EFAULT;
         }
@@ -187,13 +190,20 @@ static int groups16_to_user(u16 __user *grouplist, struct group_info *group_info
 
 static int groups16_from_user(struct group_info *group_info, u16 __user *grouplist)
 {
+        struct user_namespace *user_ns = current_user_ns();
         int i;
         u16 group;
+        kgid_t kgid;
 
         for (i = 0; i < group_info->ngroups; i++) {
                 if (get_user(group, grouplist+i))
                         return  -EFAULT;
-                GROUP_AT(group_info, i) = (gid_t)group;
+
+                kgid = make_kgid(user_ns, (gid_t)group);
+                if (!gid_valid(kgid))
+                        return -EINVAL;
+
+                GROUP_AT(group_info, i) = kgid;
         }
 
         return 0;
diff --git a/fs/nfsd/auth.c b/fs/nfsd/auth.c
index 79717a40daba..204438cc914e 100644
--- a/fs/nfsd/auth.c
+++ b/fs/nfsd/auth.c
@@ -1,6 +1,7 @@
 /* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */
 
 #include <linux/sched.h>
+#include <linux/user_namespace.h>
 #include "nfsd.h"
 #include "auth.h"
 
@@ -56,8 +57,8 @@ int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
                         goto oom;
 
                 for (i = 0; i < rqgi->ngroups; i++) {
-                        if (!GROUP_AT(rqgi, i))
-                                GROUP_AT(gi, i) = exp->ex_anon_gid;
+                        if (gid_eq(GLOBAL_ROOT_GID, GROUP_AT(rqgi, i)))
+                                GROUP_AT(gi, i) = make_kgid(&init_user_ns, exp->ex_anon_gid);
                         else
                                 GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
                 }
diff --git a/fs/proc/array.c b/fs/proc/array.c
index f9bd395b3473..36a0a9192ece 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -81,6 +81,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/ptrace.h>
 #include <linux/tracehook.h>
+#include <linux/user_namespace.h>
 
 #include <asm/pgtable.h>
 #include <asm/processor.h>
@@ -161,6 +162,7 @@ static inline const char *get_task_state(struct task_struct *tsk)
 static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
                                 struct pid *pid, struct task_struct *p)
 {
+        struct user_namespace *user_ns = current_user_ns();
         struct group_info *group_info;
         int g;
         struct fdtable *fdt = NULL;
@@ -205,7 +207,8 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
         task_unlock(p);
 
         for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++)
-                seq_printf(m, "%d ", GROUP_AT(group_info, g));
+                seq_printf(m, "%d ",
+                           from_kgid_munged(user_ns, GROUP_AT(group_info, g)));
         put_cred(cred);
 
         seq_putc(m, '\n');
diff --git a/include/linux/cred.h b/include/linux/cred.h
index 2c60ec802678..0ab3cda4a774 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -17,6 +17,7 @@
 #include <linux/key.h>
 #include <linux/selinux.h>
 #include <linux/atomic.h>
+#include <linux/uidgid.h>
 
 struct user_struct;
 struct cred;
@@ -26,14 +27,14 @@ struct inode;
  * COW Supplementary groups list
  */
 #define NGROUPS_SMALL           32
-#define NGROUPS_PER_BLOCK       ((unsigned int)(PAGE_SIZE / sizeof(gid_t)))
+#define NGROUPS_PER_BLOCK       ((unsigned int)(PAGE_SIZE / sizeof(kgid_t)))
 
 struct group_info {
         atomic_t        usage;
         int             ngroups;
         int             nblocks;
-        gid_t           small_block[NGROUPS_SMALL];
-        gid_t           *blocks[0];
+        kgid_t          small_block[NGROUPS_SMALL];
+        kgid_t          *blocks[0];
 };
 
 /**
@@ -66,7 +67,7 @@ extern struct group_info init_groups;
 extern void groups_free(struct group_info *);
 extern int set_current_groups(struct group_info *);
 extern int set_groups(struct cred *, struct group_info *);
-extern int groups_search(const struct group_info *, gid_t);
+extern int groups_search(const struct group_info *, kgid_t);
 
 /* access the groups "array" with this macro */
 #define GROUP_AT(gi, i) \
diff --git a/kernel/groups.c b/kernel/groups.c
index 99b53d1eb7ea..84156f2d4c8c 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -31,7 +31,7 @@ struct group_info *groups_alloc(int gidsetsize)
                 group_info->blocks[0] = group_info->small_block;
         else {
                 for (i = 0; i < nblocks; i++) {
-                        gid_t *b;
+                        kgid_t *b;
                         b = (void *)__get_free_page(GFP_USER);
                         if (!b)
                                 goto out_undo_partial_alloc;
@@ -66,18 +66,15 @@ EXPORT_SYMBOL(groups_free);
 static int groups_to_user(gid_t __user *grouplist,
                           const struct group_info *group_info)
 {
+        struct user_namespace *user_ns = current_user_ns();
         int i;
         unsigned int count = group_info->ngroups;
 
-        for (i = 0; i < group_info->nblocks; i++) {
-                unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
-                unsigned int len = cp_count * sizeof(*grouplist);
-
-                if (copy_to_user(grouplist, group_info->blocks[i], len))
+        for (i = 0; i < count; i++) {
+                gid_t gid;
+                gid = from_kgid_munged(user_ns, GROUP_AT(group_info, i));
+                if (put_user(gid, grouplist+i))
                         return -EFAULT;
-
-                grouplist += NGROUPS_PER_BLOCK;
-                count -= cp_count;
         }
         return 0;
 }
@@ -86,18 +83,21 @@ static int groups_to_user(gid_t __user *grouplist,
 static int groups_from_user(struct group_info *group_info,
     gid_t __user *grouplist)
 {
+        struct user_namespace *user_ns = current_user_ns();
         int i;
         unsigned int count = group_info->ngroups;
 
-        for (i = 0; i < group_info->nblocks; i++) {
-                unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
-                unsigned int len = cp_count * sizeof(*grouplist);
-
-                if (copy_from_user(group_info->blocks[i], grouplist, len))
+        for (i = 0; i < count; i++) {
+                gid_t gid;
+                kgid_t kgid;
+                if (get_user(gid, grouplist+i))
                         return -EFAULT;
 
-                grouplist += NGROUPS_PER_BLOCK;
-                count -= cp_count;
+                kgid = make_kgid(user_ns, gid);
+                if (!gid_valid(kgid))
+                        return -EINVAL;
+
+                GROUP_AT(group_info, i) = kgid;
         }
         return 0;
 }
@@ -117,9 +117,9 @@ static void groups_sort(struct group_info *group_info)
                 for (base = 0; base < max; base++) {
                         int left = base;
                         int right = left + stride;
-                        gid_t tmp = GROUP_AT(group_info, right);
+                        kgid_t tmp = GROUP_AT(group_info, right);
 
-                        while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
+                        while (left >= 0 && gid_gt(GROUP_AT(group_info, left), tmp)) {
                                 GROUP_AT(group_info, right) =
                                     GROUP_AT(group_info, left);
                                 right = left;
@@ -132,7 +132,7 @@ static void groups_sort(struct group_info *group_info)
 }
 
 /* a simple bsearch */
-int groups_search(const struct group_info *group_info, gid_t grp)
+int groups_search(const struct group_info *group_info, kgid_t grp)
 {
         unsigned int left, right;
 
@@ -143,9 +143,9 @@ int groups_search(const struct group_info *group_info, gid_t grp)
         right = group_info->ngroups;
         while (left < right) {
                 unsigned int mid = (left+right)/2;
-                if (grp > GROUP_AT(group_info, mid))
+                if (gid_gt(grp, GROUP_AT(group_info, mid)))
                         left = mid + 1;
-                else if (grp < GROUP_AT(group_info, mid))
+                else if (gid_lt(grp, GROUP_AT(group_info, mid)))
                         right = mid;
                 else
                         return 1;
@@ -262,7 +262,8 @@ int in_group_p(gid_t grp)
         int retval = 1;
 
         if (grp != cred->fsgid)
-                retval = groups_search(cred->group_info, grp);
+                retval = groups_search(cred->group_info,
+                                       make_kgid(cred->user_ns, grp));
         return retval;
 }
 
@@ -274,7 +275,8 @@ int in_egroup_p(gid_t grp)
         int retval = 1;
 
         if (grp != cred->egid)
-                retval = groups_search(cred->group_info, grp);
+                retval = groups_search(cred->group_info,
+                                       make_kgid(cred->user_ns, grp));
         return retval;
 }
 
diff --git a/kernel/uid16.c b/kernel/uid16.c
index 51c6e89e8619..e530bc34c4cf 100644
--- a/kernel/uid16.c
+++ b/kernel/uid16.c
@@ -134,11 +134,14 @@ SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
 static int groups16_to_user(old_gid_t __user *grouplist,
     struct group_info *group_info)
 {
+        struct user_namespace *user_ns = current_user_ns();
         int i;
         old_gid_t group;
+        kgid_t kgid;
 
         for (i = 0; i < group_info->ngroups; i++) {
-                group = high2lowgid(GROUP_AT(group_info, i));
+                kgid = GROUP_AT(group_info, i);
+                group = high2lowgid(from_kgid_munged(user_ns, kgid));
                 if (put_user(group, grouplist+i))
                         return -EFAULT;
         }
@@ -149,13 +152,20 @@ static int groups16_to_user(old_gid_t __user *grouplist,
 static int groups16_from_user(struct group_info *group_info,
     old_gid_t __user *grouplist)
 {
+        struct user_namespace *user_ns = current_user_ns();
         int i;
         old_gid_t group;
+        kgid_t kgid;
 
         for (i = 0; i < group_info->ngroups; i++) {
                 if (get_user(group, grouplist+i))
                         return  -EFAULT;
-                GROUP_AT(group_info, i) = low2highgid(group);
+
+                kgid = make_kgid(user_ns, low2highgid(group));
+                if (!gid_valid(kgid))
+                        return -EINVAL;
+
+                GROUP_AT(group_info, i) = kgid;
         }
 
         return 0;
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 50009c787bcd..9d3044ff45b9 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -205,17 +205,22 @@ static int ping_init_sock(struct sock *sk)
         gid_t range[2];
         struct group_info *group_info = get_current_groups();
         int i, j, count = group_info->ngroups;
+        kgid_t low, high;
 
         inet_get_ping_group_range_net(net, range, range+1);
+        low = make_kgid(&init_user_ns, range[0]);
+        high = make_kgid(&init_user_ns, range[1]);
+        if (!gid_valid(low) || !gid_valid(high) || gid_lt(high, low))
+                return -EACCES;
+
         if (range[0] <= group && group <= range[1])
                 return 0;
 
         for (i = 0; i < group_info->nblocks; i++) {
                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
-
                 for (j = 0; j < cp_count; j++) {
-                        group = group_info->blocks[i][j];
-                        if (range[0] <= group && group <= range[1])
+                        kgid_t gid = group_info->blocks[i][j];
+                        if (gid_lte(low, gid) && gid_lte(gid, high))
                                 return 0;
                 }
 
diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c
index 75762f346975..6ed6f201b022 100644
--- a/net/sunrpc/auth_generic.c
+++ b/net/sunrpc/auth_generic.c
@@ -160,8 +160,8 @@ generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
         if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
                 goto out_nomatch;
         for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
-                if (GROUP_AT(gcred->acred.group_info, i) !=
-                                GROUP_AT(acred->group_info, i))
+                if (!gid_eq(GROUP_AT(gcred->acred.group_info, i),
+                                GROUP_AT(acred->group_info, i)))
                         goto out_nomatch;
         }
 out_match:
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 1600cfb1618c..28b62dbb6d1e 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -41,6 +41,7 @@
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/pagemap.h>
+#include <linux/user_namespace.h>
 
 #include <linux/sunrpc/auth_gss.h>
 #include <linux/sunrpc/gss_err.h>
@@ -470,9 +471,13 @@ static int rsc_parse(struct cache_detail *cd,
                 status = -EINVAL;
                 for (i=0; i<N; i++) {
                         gid_t gid;
+                        kgid_t kgid;
                         if (get_int(&mesg, &gid))
                                 goto out;
-                        GROUP_AT(rsci.cred.cr_group_info, i) = gid;
+                        kgid = make_kgid(&init_user_ns, gid);
+                        if (!gid_valid(kgid))
+                                goto out;
+                        GROUP_AT(rsci.cred.cr_group_info, i) = kgid;
                 }
 
                 /* mech name */
diff --git a/net/sunrpc/auth_unix.c b/net/sunrpc/auth_unix.c
index e50502d8ceb7..52c5abdee211 100644
--- a/net/sunrpc/auth_unix.c
+++ b/net/sunrpc/auth_unix.c
@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/auth.h>
+#include <linux/user_namespace.h>
 
 #define NFS_NGROUPS     16
 
@@ -78,8 +79,11 @@ unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
                 groups = NFS_NGROUPS;
 
         cred->uc_gid = acred->gid;
-        for (i = 0; i < groups; i++)
-                cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
+        for (i = 0; i < groups; i++) {
+                gid_t gid;
+                gid = from_kgid(&init_user_ns, GROUP_AT(acred->group_info, i));
+                cred->uc_gids[i] = gid;
+        }
         if (i < NFS_NGROUPS)
                 cred->uc_gids[i] = NOGROUP;
 
@@ -126,9 +130,12 @@ unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
                 groups = acred->group_info->ngroups;
         if (groups > NFS_NGROUPS)
                 groups = NFS_NGROUPS;
-        for (i = 0; i < groups ; i++)
-                if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
+        for (i = 0; i < groups ; i++) {
+                gid_t gid;
+                gid = from_kgid(&init_user_ns, GROUP_AT(acred->group_info, i));
+                if (cred->uc_gids[i] != gid)
                         return 0;
+        }
         if (groups < NFS_NGROUPS &&
             cred->uc_gids[groups] != NOGROUP)
                 return 0;
diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 521d8f7dc833..71ec8530ec8c 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -14,6 +14,7 @@
 #include <net/sock.h>
 #include <net/ipv6.h>
 #include <linux/kernel.h>
+#include <linux/user_namespace.h>
 #define RPCDBG_FACILITY RPCDBG_AUTH
 
 #include <linux/sunrpc/clnt.h>
@@ -530,11 +531,15 @@ static int unix_gid_parse(struct cache_detail *cd,
 
         for (i = 0 ; i < gids ; i++) {
                 int gid;
+                kgid_t kgid;
                 rv = get_int(&mesg, &gid);
                 err = -EINVAL;
                 if (rv)
                         goto out;
-                GROUP_AT(ug.gi, i) = gid;
+                kgid = make_kgid(&init_user_ns, gid);
+                if (!gid_valid(kgid))
+                        goto out;
+                GROUP_AT(ug.gi, i) = kgid;
         }
 
         ugp = unix_gid_lookup(cd, uid);
@@ -563,6 +568,7 @@ static int unix_gid_show(struct seq_file *m,
                          struct cache_detail *cd,
                          struct cache_head *h)
 {
+        struct user_namespace *user_ns = current_user_ns();
         struct unix_gid *ug;
         int i;
         int glen;
@@ -580,7 +586,7 @@ static int unix_gid_show(struct seq_file *m,
 
         seq_printf(m, "%u %d:", ug->uid, glen);
         for (i = 0; i < glen; i++)
-                seq_printf(m, " %d", GROUP_AT(ug->gi, i));
+                seq_printf(m, " %d", from_kgid_munged(user_ns, GROUP_AT(ug->gi, i)));
         seq_printf(m, "\n");
         return 0;
 }
@@ -831,8 +837,12 @@ svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
         cred->cr_group_info = groups_alloc(slen);
         if (cred->cr_group_info == NULL)
                 return SVC_CLOSE;
-        for (i = 0; i < slen; i++)
-                GROUP_AT(cred->cr_group_info, i) = svc_getnl(argv);
+        for (i = 0; i < slen; i++) {
+                kgid_t kgid = make_kgid(&init_user_ns, svc_getnl(argv));
+                if (!gid_valid(kgid))
+                        goto badcred;
+                GROUP_AT(cred->cr_group_info, i) = kgid;
+        }
         if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
                 *authp = rpc_autherr_badverf;
                 return SVC_DENIED;
diff --git a/security/keys/permission.c b/security/keys/permission.c
index e146cbd714bd..5442900d2929 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -53,7 +53,8 @@ int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
                         goto use_these_perms;
                 }
 
-                ret = groups_search(cred->group_info, key->gid);
+                ret = groups_search(cred->group_info,
+                                    make_kgid(current_user_ns(), key->gid));
                 if (ret) {
                         kperm = key->perm >> 8;
                         goto use_these_perms;