diff options
Diffstat (limited to 'Documentation/security/credentials.rst')
| -rw-r--r-- | Documentation/security/credentials.rst | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/Documentation/security/credentials.rst b/Documentation/security/credentials.rst index 282e79feee6a..357328d566c8 100644 --- a/Documentation/security/credentials.rst +++ b/Documentation/security/credentials.rst @@ -323,7 +323,6 @@ credentials (the value is simply returned in each case):: uid_t current_fsuid(void) Current's file access UID gid_t current_fsgid(void) Current's file access GID kernel_cap_t current_cap(void) Current's effective capabilities - void *current_security(void) Current's LSM security pointer struct user_struct *current_user(void) Current's user account There are also convenience wrappers for retrieving specific associated pairs of @@ -453,9 +452,9 @@ still at this point. When replacing the group list, the new list must be sorted before it is added to the credential, as a binary search is used to test for -membership. In practice, this means :c:func:`groups_sort` should be -called before :c:func:`set_groups` or :c:func:`set_current_groups`. -:c:func:`groups_sort)` must not be called on a ``struct group_list`` which +membership. In practice, this means groups_sort() should be +called before set_groups() or set_current_groups(). +groups_sort() must not be called on a ``struct group_list`` which is shared as it may permute elements as part of the sorting process even if the array is already sorted. @@ -548,6 +547,10 @@ pointer will not change over the lifetime of the file struct, and nor will the contents of the cred struct pointed to, barring the exceptions listed above (see the Task Credentials section). +To avoid "confused deputy" privilege escalation attacks, access control checks +during subsequent operations on an opened file should use these credentials +instead of "current"'s credentials, as the file may have been passed to a more +privileged process. Overriding the VFS's Use of Credentials ======================================= |