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authorMicah Morton <mortonm@chromium.org>2019-01-22 14:42:09 -0800
committerJames Morris <james.morris@microsoft.com>2019-01-25 11:22:43 -0800
commit40852275a94afb3e836be9248399e036982d1a79 (patch)
tree97db7b5d7dfae0ecd678b57bc861e60e949afe44 /kernel/sys.c
parent4b42564181d683d767b495d7041b1f229468042f (diff)
downloadlinux-40852275a94afb3e836be9248399e036982d1a79.tar.bz2
LSM: add SafeSetID module that gates setid calls
This change ensures that the set*uid family of syscalls in kernel/sys.c (setreuid, setuid, setresuid, setfsuid) all call ns_capable_common with the CAP_OPT_INSETID flag, so capability checks in the security_capable hook can know whether they are being called from within a set*uid syscall. This change is a no-op by itself, but is needed for the proposed SafeSetID LSM. Signed-off-by: Micah Morton <mortonm@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.morris@microsoft.com>
Diffstat (limited to 'kernel/sys.c')
-rw-r--r--kernel/sys.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index f7eb62eceb24..c5f875048aef 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -516,7 +516,7 @@ long __sys_setreuid(uid_t ruid, uid_t euid)
new->uid = kruid;
if (!uid_eq(old->uid, kruid) &&
!uid_eq(old->euid, kruid) &&
- !ns_capable(old->user_ns, CAP_SETUID))
+ !ns_capable_setid(old->user_ns, CAP_SETUID))
goto error;
}
@@ -525,7 +525,7 @@ long __sys_setreuid(uid_t ruid, uid_t euid)
if (!uid_eq(old->uid, keuid) &&
!uid_eq(old->euid, keuid) &&
!uid_eq(old->suid, keuid) &&
- !ns_capable(old->user_ns, CAP_SETUID))
+ !ns_capable_setid(old->user_ns, CAP_SETUID))
goto error;
}
@@ -584,7 +584,7 @@ long __sys_setuid(uid_t uid)
old = current_cred();
retval = -EPERM;
- if (ns_capable(old->user_ns, CAP_SETUID)) {
+ if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
new->suid = new->uid = kuid;
if (!uid_eq(kuid, old->uid)) {
retval = set_user(new);
@@ -646,7 +646,7 @@ long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
old = current_cred();
retval = -EPERM;
- if (!ns_capable(old->user_ns, CAP_SETUID)) {
+ if (!ns_capable_setid(old->user_ns, CAP_SETUID)) {
if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
!uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
goto error;
@@ -814,7 +814,7 @@ long __sys_setfsuid(uid_t uid)
if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
- ns_capable(old->user_ns, CAP_SETUID)) {
+ ns_capable_setid(old->user_ns, CAP_SETUID)) {
if (!uid_eq(kuid, old->fsuid)) {
new->fsuid = kuid;
if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)