Eric Lee / smarc-ti-linux-kernel

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Commit e726c9a0a24b1381b2714dbeca322ab446fccb4a

Authored by Eric W. Biederman
Committed by Greg Kroah-Hartman
1 parent 462c8c0b35

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" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Showing 4 changed files with 11 additions and 3 deletions Side-by-side Diff

arch/s390/kernel/compat_linux.c
Diff comments   View file @ e726c9a
... ... @@ -249,7 +249,7 @@
249 249 struct group_info *group_info;
250 250 int retval;
251 251  
252   - if (!capable(CAP_SETGID))
  252 + if (!may_setgroups())
253 253 return -EPERM;
254 254 if ((unsigned)gidsetsize > NGROUPS_MAX)
255 255 return -EINVAL;
include/linux/cred.h
Diff comments   View file @ e726c9a
... ... @@ -68,6 +68,7 @@
68 68 extern int set_current_groups(struct group_info *);
69 69 extern void set_groups(struct cred *, struct group_info *);
70 70 extern int groups_search(const struct group_info *, kgid_t);
  71 +extern bool may_setgroups(void);
71 72  
72 73 /* access the groups "array" with this macro */
73 74 #define GROUP_AT(gi, i) \
... ... @@ -213,6 +213,13 @@
213 213 return i;
214 214 }
215 215  
  216 +bool may_setgroups(void)
  217 +{
  218 + struct user_namespace *user_ns = current_user_ns();
  219 +
  220 + return ns_capable(user_ns, CAP_SETGID);
  221 +}
  222 +
216 223 /*
217 224 * SMP: Our groups are copy-on-write. We can set them safely
218 225 * without another task interfering.
... ... @@ -223,7 +230,7 @@
223 230 struct group_info *group_info;
224 231 int retval;
225 232  
226   - if (!ns_capable(current_user_ns(), CAP_SETGID))
  233 + if (!may_setgroups())
227 234 return -EPERM;
228 235 if ((unsigned)gidsetsize > NGROUPS_MAX)
229 236 return -EINVAL;
... ... @@ -176,7 +176,7 @@
176 176 struct group_info *group_info;
177 177 int retval;
178 178  
179   - if (!ns_capable(current_user_ns(), CAP_SETGID))
  179 + if (!may_setgroups())
180 180 return -EPERM;
181 181 if ((unsigned)gidsetsize > NGROUPS_MAX)
182 182 return -EINVAL;