The patch titled Subject: device_cgroup: fix unchecked cgroup parent usage has been removed from the -mm tree. Its filename was device_cgroup-fix-unchecked-cgroup-parent-usage.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Aristeu Rozanski <aris@xxxxxxxxxx> Subject: device_cgroup: fix unchecked cgroup parent usage In 4cef7299b478687 ("device_cgroup: add proper checking when changing default behavior") the cgroup parent usage is unchecked. root will not have a parent and trying to use device.{allow,deny} will cause a null pointer dereference. For some reason my stressing scripts didn't test the root directory so I didn't catch it on my regular tests. Signed-off-by: Aristeu Rozanski <aris@xxxxxxxxxx> Cc: Li Zefan <lizefan@xxxxxxxxxx> Cc: James Morris <jmorris@xxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxx> Acked-by: Serge E. Hallyn <serge.hallyn@xxxxxxxxxx> Cc: Jiri Slaby <jslaby@xxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- security/device_cgroup.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff -puN security/device_cgroup.c~device_cgroup-fix-unchecked-cgroup-parent-usage security/device_cgroup.c --- a/security/device_cgroup.c~device_cgroup-fix-unchecked-cgroup-parent-usage +++ a/security/device_cgroup.c @@ -352,6 +352,8 @@ static int parent_has_perm(struct dev_cg */ static inline int may_allow_all(struct dev_cgroup *parent) { + if (!parent) + return 1; return parent->behavior == DEVCG_DEFAULT_ALLOW; } @@ -376,11 +378,14 @@ static int devcgroup_update_access(struc int count, rc; struct dev_exception_item ex; struct cgroup *p = devcgroup->css.cgroup; - struct dev_cgroup *parent = cgroup_to_devcgroup(p->parent); + struct dev_cgroup *parent = NULL; if (!capable(CAP_SYS_ADMIN)) return -EPERM; + if (p->parent) + parent = cgroup_to_devcgroup(p->parent); + memset(&ex, 0, sizeof(ex)); b = buffer; @@ -391,11 +396,14 @@ static int devcgroup_update_access(struc if (!may_allow_all(parent)) return -EPERM; dev_exception_clean(devcgroup); + devcgroup->behavior = DEVCG_DEFAULT_ALLOW; + if (!parent) + break; + rc = dev_exceptions_copy(&devcgroup->exceptions, &parent->exceptions); if (rc) return rc; - devcgroup->behavior = DEVCG_DEFAULT_ALLOW; break; case DEVCG_DENY: dev_exception_clean(devcgroup); _ Patches currently in -mm which might be from aris@xxxxxxxxxx are linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html